Refactor calling convention settings. (#304)

Add a calling-convention setting to the `Flags` used as part of the
`TargetIsa`. This allows Cretonne code that generates calls to use the
correct convention, such as when emitting libcalls during legalization
or when the wasm frontend is decoding functions. This setting can be
overridden per-function.

This also adds "fast", "cold", and "fastcall" conventions, with "fast"
as the new default. Note that "fast" and "cold" are not intended to be
ABI-compatible across Cretonne versions.

This will also ensure Windows users will get an `unimplemented!` rather
than silent calling-convention mismatches, which reflects the fact that
Windows calling conventions are not yet implemented.

This also renames SpiderWASM, which isn't camel-case, to Baldrdash,
which is, and which is also a more relevant name.

cranelift/docs/heapex-dyn.cton

@@ -1,6 +1,6 @@
 test verifier
 
-function %add_members(i32) -> f32 spiderwasm {
+function %add_members(i32) -> f32 baldrdash {
     gv0 = vmctx+64
     gv1 = vmctx+72
     heap0 = dynamic gv0, min 0x1000, bound gv1, guard 0

cranelift/docs/heapex-sm32.cton

@@ -1,6 +1,6 @@
 test verifier
 
-function %add_members(i32) -> f32 spiderwasm {
+function %add_members(i32) -> f32 baldrdash {
     gv0 = vmctx+64
     heap0 = static gv0, min 0x1000, bound 0x10_0000, guard 0x1000
 

cranelift/docs/heapex-sm64.cton

@@ -1,6 +1,6 @@
 test verifier
 
-function %add_members(i32) -> f32 spiderwasm {
+function %add_members(i32) -> f32 baldrdash {
     gv0 = vmctx+64
     heap0 = static gv0, min 0x1000, bound 0x1_0000_0000, guard 0x8000_0000
 

cranelift/docs/langref.rst

@@ -399,7 +399,28 @@ convention:
     param        : type [paramext] [paramspecial]
     paramext     : "uext" | "sext"
     paramspecial : "sret" | "link" | "fp" | "csr" | "vmctx"
-    callconv     : "system_v" | "spiderwasm"
+    callconv     : "fast" | "cold" | "system_v" | "fastcall" | "baldrdash"
+
+A function's calling convention determines exactly how arguments and return
+values are passed, and how stack frames are managed. Since all of these details
+depend on both the instruction set /// architecture and possibly the operating
+system, a function's calling convention is only fully determined by a
+`(TargetIsa, CallConv)` tuple.
+
+========== ===========================================
+Name       Description
+========== ===========================================
+fast       not-ABI-stable convention for best performance
+cold       not-ABI-stable convention for infrequently executed code
+system_v   System V-style convention used on many platforms
+fastcall   Windows "fastcall" convention, also used for x64 and ARM
+baldrdash  SpiderMonkey WebAssembly convention
+========== ===========================================
+
+The "not-ABI-stable" conventions do not follow an external specification and
+may change between versions of Cretonne.
+
+The "fastcall" convention is not yet implemented.
 
 Parameters and return values have flags whose meaning is mostly target
 dependent. These flags support interfacing with code produced by other

cranelift/filetests/isa/riscv/parse-encoding.cton

@@ -3,7 +3,7 @@ test legalizer
 isa riscv
 
 function %parse_encoding(i32 [%x5]) -> i32 [%x10] {
-    ; check: function %parse_encoding(i32 [%x5], i32 link [%x1]) -> i32 [%x10], i32 link [%x1] system_v {
+    ; check: function %parse_encoding(i32 [%x5], i32 link [%x1]) -> i32 [%x10], i32 link [%x1] fast {
 
     sig0 = (i32 [%x10]) -> i32 [%x10] system_v
     ; check: sig0 = (i32 [%x10]) -> i32 [%x10] system_v

cranelift/filetests/isa/x86/abi64.cton

@@ -19,8 +19,8 @@ ebb0:
     return
 }
 
-function %pass_stack_int64(i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64 vmctx) spiderwasm {
+function %pass_stack_int64(i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64 vmctx) baldrdash {
-    sig0 = (i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64 vmctx) spiderwasm
+    sig0 = (i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64, i64 vmctx) baldrdash
     fn0 = u0:0 sig0
 
 ebb0(v0: i64, v1: i64, v2: i64, v3: i64, v4: i64, v5: i64, v6: i64, v7: i64, v8: i64, v9: i64, v10: i64, v11: i64, v12: i64, v13: i64, v14: i64, v15: i64, v16: i64, v17: i64, v18: i64, v19: i64, v20: i64):

cranelift/filetests/isa/x86/legalize-libcall.cton

@@ -10,7 +10,7 @@ ebb0(v0: f32):
     v1 = floor v0
     return v1
 }
-; check: function %floor(f32 [%xmm0]) -> f32 [%xmm0] system_v {
+; check: function %floor(f32 [%xmm0]) -> f32 [%xmm0] fast {
-; check: sig0 = (f32) -> f32 system_v
+; check: sig0 = (f32) -> f32 fast
 ; check: fn0 = %FloorF32 sig0
 ; check: v1 = call fn0(v0)

cranelift/filetests/isa/x86/legalize-memory.cton

@@ -44,7 +44,7 @@ ebb1:
 
 ; SpiderMonkey VM-style static 4+2 GB heap.
 ; This eliminates bounds checks completely for offsets < 2GB.
-function %staticheap_sm64(i32, i64 vmctx) -> f32 spiderwasm {
+function %staticheap_sm64(i32, i64 vmctx) -> f32 baldrdash {
     gv0 = vmctx+64
     heap0 = static gv0, min 0x1000, bound 0x1_0000_0000, guard 0x8000_0000
 
@@ -65,7 +65,7 @@ ebb0(v0: i32, v999: i64):
     return v4
 }
 
-function %staticheap_static_oob_sm64(i32, i64 vmctx) -> f32 spiderwasm {
+function %staticheap_static_oob_sm64(i32, i64 vmctx) -> f32 baldrdash {
     gv0 = vmctx+64
     heap0 = static gv0, min 0x1000, bound 0x1000_0000, guard 0x8000_0000
 
@@ -88,7 +88,7 @@ ebb0(v0: i32, v999: i64):
 
 ; SpiderMonkey VM-style static 4+2 GB heap.
 ; Offsets >= 2 GB do require a boundscheck.
-function %staticheap_sm64(i32, i64 vmctx) -> f32 spiderwasm {
+function %staticheap_sm64(i32, i64 vmctx) -> f32 baldrdash {
     gv0 = vmctx+64
     heap0 = static gv0, min 0x1000, bound 0x1_0000_0000, guard 0x8000_0000
 
@@ -112,7 +112,7 @@ ebb0(v0: i32, v999: i64):
 
 ; Stack overflow check.
 ; The stack limit is stored in a pointer-sized global variable.
-function %stkchk(i64 vmctx) spiderwasm {
+function %stkchk(i64 vmctx) baldrdash {
     gv0 = vmctx+64
 
 ebb0(v0: i64):

cranelift/filetests/isa/x86/prologue-epilogue.cton

@@ -11,7 +11,7 @@ ebb0:
     return
 }
 
-; check: function %empty(i64 fp [%rbp]) -> i64 fp [%rbp] system_v {
+; check: function %empty(i64 fp [%rbp]) -> i64 fp [%rbp] fast {
 ; nextln:     ss0 = incoming_arg 16, offset -16
 ; nextln: 
 ; nextln: ebb0(v0: i64 [%rbp]):
@@ -29,7 +29,7 @@ ebb0:
     return
 }
 
-; check: function %one_stack_slot(i64 fp [%rbp]) -> i64 fp [%rbp] system_v {
+; check: function %one_stack_slot(i64 fp [%rbp]) -> i64 fp [%rbp] fast {
 ; nextln:     ss0 = explicit_slot 168, offset -184
 ; nextln:     ss1 = incoming_arg 16, offset -16
 ; nextln: 
@@ -52,9 +52,9 @@ ebb0:
     return
 }
 
-; check: function %call(i64 fp [%rbp]) -> i64 fp [%rbp] system_v {
+; check: function %call(i64 fp [%rbp]) -> i64 fp [%rbp] fast {
 ; nextln:     ss0 = incoming_arg 16, offset -16
-; nextln:     sig0 = () system_v
+; nextln:     sig0 = () fast
 ; nextln:     fn0 = %foo sig0
 ; nextln: 
 ; nextln: ebb0(v0: i64 [%rbp]):
@@ -98,7 +98,7 @@ ebb0(v0: i64, v1: i64):
     return
 }
 
-; check: function %no_spill(i64 [%rdi], i64 [%rsi], i64 fp [%rbp], i64 csr [%rbx], i64 csr [%r12], i64 csr [%r13], i64 csr [%r14], i64 csr [%r15]) -> i64 fp [%rbp], i64 csr [%rbx], i64 csr [%r12], i64 csr [%r13], i64 csr [%r14], i64 csr [%r15] system_v {
+; check: function %no_spill(i64 [%rdi], i64 [%rsi], i64 fp [%rbp], i64 csr [%rbx], i64 csr [%r12], i64 csr [%r13], i64 csr [%r14], i64 csr [%r15]) -> i64 fp [%rbp], i64 csr [%rbx], i64 csr [%r12], i64 csr [%r13], i64 csr [%r14], i64 csr [%r15] fast {
 ; nextln:     ss0 = incoming_arg 56, offset -56
 ; nextln: 
 ; nextln: ebb0(v0: i64 [%rdi], v1: i64 [%rsi], v15: i64 [%rbp], v16: i64 [%rbx], v17: i64 [%r12], v18: i64 [%r13], v19: i64 [%r14], v20: i64 [%r15]):
@@ -181,7 +181,7 @@ ebb0(v0: i64, v1: i64):
     return
 }
 
-; check: function %yes_spill(i64 [%rdi], i64 [%rsi], i64 fp [%rbp], i64 csr [%rbx], i64 csr [%r12], i64 csr [%r13], i64 csr [%r14], i64 csr [%r15]) -> i64 fp [%rbp], i64 csr [%rbx], i64 csr [%r12], i64 csr [%r13], i64 csr [%r14], i64 csr [%r15] system_v {
+; check: function %yes_spill(i64 [%rdi], i64 [%rsi], i64 fp [%rbp], i64 csr [%rbx], i64 csr [%r12], i64 csr [%r13], i64 csr [%r14], i64 csr [%r15]) -> i64 fp [%rbp], i64 csr [%rbx], i64 csr [%r12], i64 csr [%r13], i64 csr [%r14], i64 csr [%r15] fast {
 ; check:     ss0 = spill_slot
 
 ; check: ebb0(v16: i64 [%rdi], v17: i64 [%rsi], v48: i64 [%rbp], v49: i64 [%rbx], v50: i64 [%r12], v51: i64 [%r13], v52: i64 [%r14], v53: i64 [%r15]):

cranelift/filetests/parser/branch.cton

@@ -9,7 +9,7 @@ ebb0:
 ebb1:
     jump ebb0()
 }
-; sameln: function %minimal() system_v {
+; sameln: function %minimal() fast {
 ; nextln: ebb0:
 ; nextln:     jump ebb1
 ; nextln: 
@@ -25,7 +25,7 @@ ebb0(v90: i32):
 ebb1(v91: i32):
     jump ebb0(v91)
 }
-; sameln: function %onearg(i32) system_v {
+; sameln: function %onearg(i32) fast {
 ; nextln: ebb0(v90: i32):
 ; nextln:     jump ebb1(v90)
 ; nextln: 
@@ -41,7 +41,7 @@ ebb0(v90: i32, v91: f32):
 ebb1(v92: i32, v93: f32):
     jump ebb0(v92, v93)
 }
-; sameln: function %twoargs(i32, f32) system_v {
+; sameln: function %twoargs(i32, f32) fast {
 ; nextln: ebb0(v90: i32, v91: f32):
 ; nextln:     jump ebb1(v90, v91)
 ; nextln: 
@@ -57,7 +57,7 @@ ebb0(v90: i32):
 ebb1:
     brnz v90, ebb1()
 }
-; sameln: function %minimal(i32) system_v {
+; sameln: function %minimal(i32) fast {
 ; nextln: ebb0(v90: i32):
 ; nextln:     brz v90, ebb1
 ; nextln: 
@@ -72,7 +72,7 @@ ebb0(v90: i32, v91: f32):
 ebb1(v92: i32, v93: f32):
     brnz v90, ebb0(v92, v93)
 }
-; sameln: function %twoargs(i32, f32) system_v {
+; sameln: function %twoargs(i32, f32) fast {
 ; nextln: ebb0(v90: i32, v91: f32):
 ; nextln:     brz v90, ebb1(v90, v91)
 ; nextln: 
@@ -94,7 +94,7 @@ ebb30:
 ebb40:
     trap user4
 }
-; sameln: function %jumptable(i32) system_v {
+; sameln: function %jumptable(i32) fast {
 ; check:      jt2 = jump_table 0, 0, ebb10, ebb40, ebb20, ebb30
 ; check:      jt200 = jump_table 0
 ; check:  ebb10(v3: i32):

cranelift/filetests/parser/call.cton

@@ -5,18 +5,18 @@ function %mini() {
 ebb1:
     return
 }
-; sameln: function %mini() system_v {
+; sameln: function %mini() fast {
 ; nextln: ebb1:
 ; nextln:     return
 ; nextln: }
 
-function %r1() -> i32, f32 spiderwasm {
+function %r1() -> i32, f32 baldrdash {
 ebb1:
     v1 = iconst.i32 3
     v2 = f32const 0.0
     return v1, v2
 }
-; sameln: function %r1() -> i32, f32 spiderwasm {
+; sameln: function %r1() -> i32, f32 baldrdash {
 ; nextln: ebb1:
 ; nextln:     v1 = iconst.i32 3
 ; nextln:     v2 = f32const 0.0
@@ -25,14 +25,14 @@ ebb1:
 
 function %signatures() {
     sig10 = ()
-    sig11 = (i32, f64) -> i32, b1 spiderwasm
+    sig11 = (i32, f64) -> i32, b1 baldrdash
     fn5 = %foo sig11
     fn8 = %bar(i32) -> b1
 }
-; sameln: function %signatures() system_v {
+; sameln: function %signatures() fast {
-; check:      sig10 = () system_v
+; check:      sig10 = () fast
-; check:      sig11 = (i32, f64) -> i32, b1 spiderwasm
+; check:      sig11 = (i32, f64) -> i32, b1 baldrdash
-; check:      sig12 = (i32) -> b1 system_v
+; check:      sig12 = (i32) -> b1 fast
 ; not:        fn0
 ; check:      fn5 = %foo sig11
 ; check:      fn8 = %bar sig12
@@ -88,7 +88,7 @@ function %special1(i32 sret, i32 fp, i32 csr, i32 link) -> i32 link, i32 fp, i32
 ebb0(v1: i32, v2: i32, v3: i32, v4: i32):
     return v4, v2, v3, v1
 }
-; check: function %special1(i32 sret, i32 fp, i32 csr, i32 link) -> i32 link, i32 fp, i32 csr, i32 sret system_v {
+; check: function %special1(i32 sret, i32 fp, i32 csr, i32 link) -> i32 link, i32 fp, i32 csr, i32 sret fast {
 ; check: ebb0(v1: i32, v2: i32, v3: i32, v4: i32):
 ; check:     return v4, v2, v3, v1
 ; check: }

cranelift/filetests/parser/instruction_encoding.cton

@@ -13,7 +13,7 @@ ebb1(v0: i32 [%x8], v1: i32):
 @55 v9 = iadd v8, v7
 @a5 [Iret#5] return v0, v8
 }
-; sameln: function %foo(i32, i32) system_v {
+; sameln: function %foo(i32, i32) fast {
 ; nextln: ebb1(v0: i32 [%x8], v1: i32):
 ; nextln:     [-,-]$WS v2 = iadd v0, v1
 ; nextln:     [-]$WS trap heap_oob

cranelift/filetests/parser/keywords.cton

@@ -2,4 +2,4 @@ test cat
 
 ; 'function' is not a keyword, and can be used as the name of a function too.
 function %function() {}
-; check: function %function() system_v
+; check: function %function() fast

cranelift/filetests/parser/rewrite.cton

@@ -9,7 +9,7 @@ ebb100(v20: i32):
     v9200 = f64const 0x4.0p0
     trap user4
 }
-; sameln: function %defs() system_v {
+; sameln: function %defs() fast {
 ; nextln: ebb100(v20: i32):
 ; nextln:     v1000 = iconst.i32x8 5
 ; nextln:     v9200 = f64const 0x1.0000000000000p2
@@ -23,7 +23,7 @@ ebb100(v20: i32):
     v200 = iadd v20, v1000
     jump ebb100(v1000)
 }
-; sameln: function %use_value() system_v {
+; sameln: function %use_value() fast {
 ; nextln: ebb100(v20: i32):
 ; nextln:     v1000 = iadd_imm v20, 5
 ; nextln:     v200 = iadd v20, v1000

cranelift/filetests/parser/tiny.cton

@@ -5,7 +5,7 @@ function %minimal() {
 ebb0:
     trap user0
 }
-; sameln: function %minimal() system_v {
+; sameln: function %minimal() fast {
 ; nextln: ebb0:
 ; nextln:     trap user0
 ; nextln: }
@@ -18,7 +18,7 @@ ebb0:
     v1 = iconst.i8 6
     v2 = ishl v0, v1
 }
-; sameln: function %ivalues() system_v {
+; sameln: function %ivalues() fast {
 ; nextln: ebb0:
 ; nextln:     v0 = iconst.i32 2
 ; nextln:     v1 = iconst.i8 6
@@ -34,7 +34,7 @@ ebb0:
     v2 = bextend.b32 v1
     v3 = bxor v0, v2
 }
-; sameln: function %bvalues() system_v {
+; sameln: function %bvalues() fast {
 ; nextln: ebb0:
 ; nextln:     v0 = bconst.b32 true
 ; nextln:     v1 = bconst.b8 false
@@ -47,7 +47,7 @@ function %select() {
 ebb0(v90: i32, v91: i32, v92: b1):
     v0 = select v92, v90, v91
 }
-; sameln: function %select() system_v {
+; sameln: function %select() fast {
 ; nextln: ebb0(v90: i32, v91: i32, v92: b1):
 ; nextln:     v0 = select v92, v90, v91
 ; nextln: }
@@ -69,7 +69,7 @@ ebb0:
     v1 = extractlane v0, 3
     v2 = insertlane v0, 1, v1
 }
-; sameln: function %lanes() system_v {
+; sameln: function %lanes() fast {
 ; nextln: ebb0:
 ; nextln:     v0 = iconst.i32x4 2
 ; nextln:     v1 = extractlane v0, 3
@@ -85,7 +85,7 @@ ebb0(v90: i32, v91: i32):
     v3 = irsub_imm v91, 45
     br_icmp eq v90, v91, ebb0(v91, v90)
 }
-; sameln: function %icmp(i32, i32) system_v {
+; sameln: function %icmp(i32, i32) fast {
 ; nextln: ebb0(v90: i32, v91: i32):
 ; nextln:     v0 = icmp eq v90, v91
 ; nextln:     v1 = icmp ult v90, v91
@@ -101,7 +101,7 @@ ebb0(v90: f32, v91: f32):
     v1 = fcmp uno v90, v91
     v2 = fcmp lt v90, v91
 }
-; sameln: function %fcmp(f32, f32) system_v {
+; sameln: function %fcmp(f32, f32) fast {
 ; nextln: ebb0(v90: f32, v91: f32):
 ; nextln:     v0 = fcmp eq v90, v91
 ; nextln:     v1 = fcmp uno v90, v91
@@ -115,7 +115,7 @@ ebb0(v90: i32, v91: f32):
     v0 = bitcast.i8x4 v90
     v1 = bitcast.i32 v91
 }
-; sameln: function %bitcast(i32, f32) system_v {
+; sameln: function %bitcast(i32, f32) fast {
 ; nextln: ebb0(v90: i32, v91: f32):
 ; nextln:     v0 = bitcast.i8x4 v90
 ; nextln:     v1 = bitcast.i32 v91
@@ -135,7 +135,7 @@ ebb0:
     stack_store v1, ss10+2
     stack_store v2, ss2
 }
-; sameln: function %stack() system_v {
+; sameln: function %stack() fast {
 ; check:     ss2 = explicit_slot 4
 ; check:     ss3 = incoming_arg 4, offset 8
 ; check:     ss4 = outgoing_arg 4
@@ -162,7 +162,7 @@ ebb0(v1: i32):
     store aligned v3, v1+12
     store notrap aligned v3, v1-12
 }
-; sameln: function %memory(i32) system_v {
+; sameln: function %memory(i32) fast {
 ; nextln: ebb0(v1: i32):
 ; nextln:     v2 = load.i64 v1
 ; nextln:     v3 = load.i64 aligned v1
@@ -187,7 +187,7 @@ ebb0(v1: i32):
     regfill v1, ss0 -> %10
     return
 }
-; sameln: function %diversion(i32) system_v {
+; sameln: function %diversion(i32) fast {
 ; nextln:     ss0 = spill_slot 4
 ; check: ebb0(v1: i32):
 ; nextln:     regmove v1, %10 -> %20
@@ -204,7 +204,7 @@ ebb0:
     copy_special %20 -> %10
     return
 }
-; sameln: function %copy_special() system_v {
+; sameln: function %copy_special() fast {
 ; nextln: ebb0:
 ; nextln:     copy_special %10 -> %20
 ; nextln:     copy_special %20 -> %10

cranelift/filetests/regalloc/aliases.cton

@@ -2,7 +2,7 @@ test regalloc
 set is_64bit
 isa x86 haswell
 
-function %value_aliases(i32, f32, i64 vmctx) spiderwasm {
+function %value_aliases(i32, f32, i64 vmctx) baldrdash {
     gv0 = vmctx
     heap0 = static gv0, min 0x0001_0000, bound 0x0001_0000_0000, guard 0x8000_0000
 

cranelift/filetests/regalloc/iterate.cton

@@ -2,7 +2,7 @@ test regalloc
 set is_64bit
 isa x86 haswell
 
-function u0:9(i64 [%rdi], f32 [%xmm0], f64 [%xmm1], i32 [%rsi], i32 [%rdx], i64 vmctx [%r14]) -> i64 [%rax] spiderwasm {
+function u0:9(i64 [%rdi], f32 [%xmm0], f64 [%xmm1], i32 [%rsi], i32 [%rdx], i64 vmctx [%r14]) -> i64 [%rax] baldrdash {
 ebb0(v0: i64, v1: f32, v2: f64, v3: i32, v4: i32, v5: i64):
     v32 = iconst.i32 0
     v6 = bitcast.f32 v32
@@ -104,9 +104,9 @@ ebb1(v31: i64):
     return v31
 }
 
-function u0:26(i64 vmctx [%r14]) -> i64 [%rax] spiderwasm {
+function u0:26(i64 vmctx [%r14]) -> i64 [%rax] baldrdash {
     gv0 = vmctx+48
-    sig0 = (i32 [%rdi], i64 [%rsi], i64 vmctx [%r14], i64 sigid [%rbx]) -> i64 [%rax] spiderwasm
+    sig0 = (i32 [%rdi], i64 [%rsi], i64 vmctx [%r14], i64 sigid [%rbx]) -> i64 [%rax] baldrdash
 
 ebb0(v0: i64):
     v1 = iconst.i32 32

cranelift/filetests/regalloc/unreachable_code.cton

@@ -6,7 +6,7 @@ isa x86 haswell
 
 ; This function contains unreachable blocks which trip up the register
 ; allocator if they don't get cleared out.
-function %unreachable_blocks(i64 vmctx) -> i32 spiderwasm {
+function %unreachable_blocks(i64 vmctx) -> i32 baldrdash {
 ebb0(v0: i64):
     v1 = iconst.i32 0
     v2 = iconst.i32 0

lib/codegen/meta/base/settings.py

@@ -29,6 +29,21 @@ enable_verifier = BoolSetting(
 
 is_64bit = BoolSetting("Enable 64-bit code generation")
 
+call_conv = EnumSetting(
+        """
+        Default calling convention:
+
+        - fast: not-ABI-stable convention for best performance
+        - cold: not-ABI-stable convention for infrequently executed code
+        - system_v: System V-style convention used on many platforms
+        - fastcall: Windows "fastcall" convention, also used for x64 and ARM
+        - baldrdash: SpiderMonkey WebAssembly convention
+
+        The default calling convention may be overridden by individual
+        functions.
+        """,
+        'fast', 'cold', 'system_v', 'fastcall', 'baldrdash')
+
 # Note that Cretonne doesn't currently need an is_pie flag, because PIE is just
 # PIC where symbols can't be pre-empted, which can be expressed with the
 # `colocated` flag on external functions and global variables.
@@ -75,13 +90,13 @@ enable_atomics = BoolSetting(
         default=True)
 
 #
-# Settings specific to the `spiderwasm` calling convention.
+# Settings specific to the `baldrdash` calling convention.
 #
-spiderwasm_prologue_words = NumSetting(
+baldrdash_prologue_words = NumSetting(
         """
-        Number of pointer-sized words pushed by the spiderwasm prologue.
+        Number of pointer-sized words pushed by the baldrdash prologue.
 
-        Functions with the `spiderwasm` calling convention don't generate their
+        Functions with the `baldrdash` calling convention don't generate their
         own prologue and epilogue. They depend on externally generated code
         that pushes a fixed number of words in the prologue and restores them
         in the epilogue.

lib/codegen/meta/gen_settings.py

@@ -19,6 +19,32 @@ except ImportError:
     pass
 
 
+def gen_to_and_from_str(ty, values, fmt):
+    # type: (str, Tuple[str, ...], srcgen.Formatter) -> None
+    """
+    Emit Display and FromStr implementations for enum settings.
+    """
+    with fmt.indented('impl fmt::Display for {} {{'.format(ty), '}'):
+        with fmt.indented(
+                'fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {',
+                '}'):
+            with fmt.indented('f.write_str(match *self {', '})'):
+                for v in values:
+                    fmt.line('{}::{} => "{}",'
+                             .format(ty, camel_case(v), v))
+
+    with fmt.indented('impl str::FromStr for {} {{'.format(ty), '}'):
+        fmt.line('type Err = ();')
+        with fmt.indented(
+                'fn from_str(s: &str) -> result::Result<Self, Self::Err> {',
+                '}'):
+            with fmt.indented('match s {', '}'):
+                for v in values:
+                    fmt.line('"{}" => Ok({}::{}),'
+                             .format(v, ty, camel_case(v)))
+                fmt.line('_ => Err(()),')
+
+
 def gen_enum_types(sgrp, fmt):
     # type: (SettingGroup, srcgen.Formatter) -> None
     """
@@ -29,12 +55,14 @@ def gen_enum_types(sgrp, fmt):
             continue
         ty = camel_case(setting.name)
         fmt.doc_comment('Values for `{}`.'.format(setting))
-        fmt.line('#[derive(Debug, Copy, Clone, PartialEq, Eq)]')
+        fmt.line('#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]')
         with fmt.indented('pub enum {} {{'.format(ty), '}'):
             for v in setting.values:
                 fmt.doc_comment('`{}`.'.format(v))
                 fmt.line(camel_case(v) + ',')
 
+        gen_to_and_from_str(ty, setting.values, fmt)
+
 
 def gen_getter(setting, sgrp, fmt):
     # type: (Setting, SettingGroup, srcgen.Formatter) -> None
@@ -221,7 +249,7 @@ def gen_display(sgrp, fmt):
                 with fmt.indented('if !d.detail.is_preset() {', '}'):
                     fmt.line('write!(f, "{} = ", d.name)?;')
                     fmt.line(
-                            'TEMPLATE.format_toml_value(d.detail,' +
+                            'TEMPLATE.format_toml_value(d.detail, ' +
                             'self.bytes[d.offset as usize], f)?;')
                     fmt.line('writeln!(f)?;')
             fmt.line('Ok(())')

lib/codegen/src/ir/extfunc.rs

@@ -7,6 +7,7 @@
 
 use ir::{ArgumentLoc, ExternalName, SigRef, Type};
 use isa::{RegInfo, RegUnit};
+use settings::CallConv;
 use std::cmp;
 use std::fmt;
 use std::str::FromStr;
@@ -342,47 +343,6 @@ impl fmt::Display for ExtFuncData {
     }
 }
 
-/// A Calling convention.
-///
-/// A function's calling convention determines exactly how arguments and return values are passed,
-/// and how stack frames are managed. Since all of these details depend on both the instruction set
-/// architecture and possibly the operating system, a function's calling convention is only fully
-/// determined by a `(TargetIsa, CallConv)` tuple.
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
-pub enum CallConv {
-    /// The System V-style calling convention.
-    ///
-    /// This is the System V-style calling convention that a C compiler would
-    /// use on many platforms.
-    SystemV,
-
-    /// A JIT-compiled WebAssembly function in the SpiderMonkey VM.
-    SpiderWASM,
-}
-
-impl fmt::Display for CallConv {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        use self::CallConv::*;
-        f.write_str(match *self {
-            SystemV => "system_v",
-            SpiderWASM => "spiderwasm",
-        })
-    }
-}
-
-impl FromStr for CallConv {
-    type Err = ();
-
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        use self::CallConv::*;
-        match s {
-            "system_v" => Ok(SystemV),
-            "spiderwasm" => Ok(SpiderWASM),
-            _ => Err(()),
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -418,23 +378,30 @@ mod tests {
 
     #[test]
     fn call_conv() {
-        for &cc in &[CallConv::SystemV, CallConv::SpiderWASM] {
+        for &cc in &[
+            CallConv::Fast,
+            CallConv::Cold,
+            CallConv::SystemV,
+            CallConv::Fastcall,
+            CallConv::Baldrdash,
+        ]
+        {
             assert_eq!(Ok(cc), cc.to_string().parse())
         }
     }
 
     #[test]
     fn signatures() {
-        let mut sig = Signature::new(CallConv::SpiderWASM);
+        let mut sig = Signature::new(CallConv::Baldrdash);
-        assert_eq!(sig.to_string(), "() spiderwasm");
+        assert_eq!(sig.to_string(), "() baldrdash");
         sig.params.push(AbiParam::new(I32));
-        assert_eq!(sig.to_string(), "(i32) spiderwasm");
+        assert_eq!(sig.to_string(), "(i32) baldrdash");
         sig.returns.push(AbiParam::new(F32));
-        assert_eq!(sig.to_string(), "(i32) -> f32 spiderwasm");
+        assert_eq!(sig.to_string(), "(i32) -> f32 baldrdash");
         sig.params.push(AbiParam::new(I32.by(4).unwrap()));
-        assert_eq!(sig.to_string(), "(i32, i32x4) -> f32 spiderwasm");
+        assert_eq!(sig.to_string(), "(i32, i32x4) -> f32 baldrdash");
         sig.returns.push(AbiParam::new(B8));
-        assert_eq!(sig.to_string(), "(i32, i32x4) -> f32, b8 spiderwasm");
+        assert_eq!(sig.to_string(), "(i32, i32x4) -> f32, b8 baldrdash");
 
         // Test the offset computation algorithm.
         assert_eq!(sig.argument_bytes, None);
@@ -450,7 +417,7 @@ mod tests {
         // Writing ABI-annotated signatures.
         assert_eq!(
             sig.to_string(),
-            "(i32 [24], i32x4 [8]) -> f32, b8 spiderwasm"
+            "(i32 [24], i32x4 [8]) -> f32, b8 baldrdash"
         );
     }
 }

lib/codegen/src/ir/function.rs

@@ -6,11 +6,12 @@
 use binemit::CodeOffset;
 use entity::{EntityMap, PrimaryMap};
 use ir;
-use ir::{CallConv, DataFlowGraph, ExternalName, Layout, Signature};
+use ir::{DataFlowGraph, ExternalName, Layout, Signature};
 use ir::{Ebb, ExtFuncData, FuncRef, GlobalVar, GlobalVarData, Heap, HeapData, JumpTable,
          JumpTableData, SigRef, StackSlot, StackSlotData};
 use ir::{EbbOffsets, InstEncodings, JumpTables, SourceLocs, StackSlots, ValueLocations};
 use isa::{EncInfo, Legalize, TargetIsa, Encoding};
+use settings::CallConv;
 use std::fmt;
 use write::write_function;
 
@@ -86,7 +87,7 @@ impl Function {
 
     /// Clear all data structures in this function.
     pub fn clear(&mut self) {
-        self.signature.clear(ir::CallConv::SystemV);
+        self.signature.clear(CallConv::Fast);
         self.stack_slots.clear();
         self.global_vars.clear();
         self.heaps.clear();
@@ -99,9 +100,9 @@ impl Function {
         self.srclocs.clear();
     }
 
-    /// Create a new empty, anonymous function with a SystemV calling convention.
+    /// Create a new empty, anonymous function with a Fast calling convention.
     pub fn new() -> Self {
-        Self::with_name_signature(ExternalName::default(), Signature::new(CallConv::SystemV))
+        Self::with_name_signature(ExternalName::default(), Signature::new(CallConv::Fast))
     }
 
     /// Creates a jump table in the function, to be used by `br_table` instructions.

lib/codegen/src/ir/mod.rs

@@ -25,8 +25,7 @@ mod valueloc;
 pub use ir::builder::{InsertBuilder, InstBuilder, InstBuilderBase, InstInserterBase};
 pub use ir::dfg::{DataFlowGraph, ValueDef};
 pub use ir::entities::{Ebb, FuncRef, GlobalVar, Heap, Inst, JumpTable, SigRef, StackSlot, Value};
-pub use ir::extfunc::{AbiParam, ArgumentExtension, ArgumentPurpose, CallConv, ExtFuncData,
+pub use ir::extfunc::{AbiParam, ArgumentExtension, ArgumentPurpose, ExtFuncData, Signature};
-                      Signature};
 pub use ir::extname::ExternalName;
 pub use ir::function::Function;
 pub use ir::globalvar::GlobalVarData;

lib/codegen/src/isa/mod.rs

@@ -52,6 +52,7 @@ use isa::enc_tables::Encodings;
 use regalloc;
 use result;
 use settings;
+use settings::CallConv;
 use std::boxed::Box;
 use std::fmt;
 use timing;
@@ -252,8 +253,8 @@ pub trait TargetIsa: fmt::Display {
         let word_size = if self.flags().is_64bit() { 8 } else { 4 };
 
         // Account for the SpiderMonkey standard prologue pushes.
-        if func.signature.call_conv == ir::CallConv::SpiderWASM {
+        if func.signature.call_conv == CallConv::Baldrdash {
-            let bytes = StackSize::from(self.flags().spiderwasm_prologue_words()) * word_size;
+            let bytes = StackSize::from(self.flags().baldrdash_prologue_words()) * word_size;
             let mut ss = ir::StackSlotData::new(ir::StackSlotKind::IncomingArg, bytes);
             ss.offset = Some(-(bytes as StackOffset));
             func.stack_slots.push(ss);

lib/codegen/src/isa/x86/abi.rs

@@ -6,12 +6,12 @@ use cursor::{Cursor, CursorPosition, EncCursor};
 use ir;
 use ir::immediates::Imm64;
 use ir::stackslot::{StackOffset, StackSize};
-use ir::{AbiParam, ArgumentExtension, ArgumentLoc, ArgumentPurpose, CallConv, InstBuilder,
+use ir::{AbiParam, ArgumentExtension, ArgumentLoc, ArgumentPurpose, InstBuilder, ValueLoc};
-         ValueLoc};
 use isa::{RegClass, RegUnit, TargetIsa};
 use regalloc::RegisterSet;
 use result;
 use settings as shared_settings;
+use settings::CallConv;
 use stack_layout::layout_stack;
 use std::i32;
 
@@ -74,7 +74,7 @@ impl ArgAssigner for Args {
         }
 
         // Handle special-purpose arguments.
-        if ty.is_int() && self.call_conv == CallConv::SpiderWASM {
+        if ty.is_int() && self.call_conv == CallConv::Baldrdash {
             match arg.purpose {
                 // This is SpiderMonkey's `WasmTlsReg`.
                 ArgumentPurpose::VMContext => {
@@ -210,19 +210,20 @@ fn callee_saved_gprs_used(flags: &shared_settings::Flags, func: &ir::Function) -
 
 pub fn prologue_epilogue(func: &mut ir::Function, isa: &TargetIsa) -> result::CtonResult {
     match func.signature.call_conv {
-        ir::CallConv::SystemV => system_v_prologue_epilogue(func, isa),
+        // For now, just translate fast and cold as system_v.
-        ir::CallConv::SpiderWASM => spiderwasm_prologue_epilogue(func, isa),
+        CallConv::Fast | CallConv::Cold | CallConv::SystemV => {
+            system_v_prologue_epilogue(func, isa)
+        }
+        CallConv::Fastcall => unimplemented!("Windows calling conventions"),
+        CallConv::Baldrdash => baldrdash_prologue_epilogue(func, isa),
     }
 }
 
-pub fn spiderwasm_prologue_epilogue(
+pub fn baldrdash_prologue_epilogue(func: &mut ir::Function, isa: &TargetIsa) -> result::CtonResult {
-    func: &mut ir::Function,
+    // Baldrdash on 32-bit x86 always aligns its stack pointer to 16 bytes.
-    isa: &TargetIsa,
-) -> result::CtonResult {
-    // Spiderwasm on 32-bit x86 always aligns its stack pointer to 16 bytes.
     let stack_align = 16;
     let word_size = if isa.flags().is_64bit() { 8 } else { 4 };
-    let bytes = StackSize::from(isa.flags().spiderwasm_prologue_words()) * word_size;
+    let bytes = StackSize::from(isa.flags().baldrdash_prologue_words()) * word_size;
 
     let mut ss = ir::StackSlotData::new(ir::StackSlotKind::IncomingArg, bytes);
     ss.offset = Some(-(bytes as StackOffset));

lib/codegen/src/legalizer/libcall.rs

@@ -3,9 +3,10 @@
 use ir;
 use ir::InstBuilder;
 use std::vec::Vec;
+use isa::TargetIsa;
 
 /// Try to expand `inst` as a library call, returning true is successful.
-pub fn expand_as_libcall(inst: ir::Inst, func: &mut ir::Function) -> bool {
+pub fn expand_as_libcall(inst: ir::Inst, func: &mut ir::Function, isa: &TargetIsa) -> bool {
     // Does the opcode/ctrl_type combo even have a well-known runtime library name.
     let libcall =
         match ir::LibCall::for_inst(func.dfg[inst].opcode(), func.dfg.ctrl_typevar(inst)) {
@@ -13,7 +14,8 @@ pub fn expand_as_libcall(inst: ir::Inst, func: &mut ir::Function) -> bool {
             None => return false,
         };
 
-    let funcref = find_funcref(libcall, func).unwrap_or_else(|| make_funcref(libcall, inst, func));
+    let funcref =
+        find_funcref(libcall, func).unwrap_or_else(|| make_funcref(libcall, inst, func, isa));
 
     // Now we convert `inst` to a call. First save the arguments.
     let mut args = Vec::new();
@@ -44,9 +46,14 @@ fn find_funcref(libcall: ir::LibCall, func: &ir::Function) -> Option<ir::FuncRef
 }
 
 /// Create a funcref for `libcall` with a signature matching `inst`.
-fn make_funcref(libcall: ir::LibCall, inst: ir::Inst, func: &mut ir::Function) -> ir::FuncRef {
+fn make_funcref(
-    // Start with a system_v calling convention. We'll give the ISA a chance to change it.
+    libcall: ir::LibCall,
-    let mut sig = ir::Signature::new(ir::CallConv::SystemV);
+    inst: ir::Inst,
+    func: &mut ir::Function,
+    isa: &TargetIsa,
+) -> ir::FuncRef {
+    // Start with a fast calling convention. We'll give the ISA a chance to change it.
+    let mut sig = ir::Signature::new(isa.flags().call_conv());
     for &v in func.dfg.inst_args(inst) {
         sig.params.push(ir::AbiParam::new(func.dfg.value_type(v)));
     }

lib/codegen/src/legalizer/mod.rs

@@ -91,7 +91,7 @@ pub fn legalize_function(func: &mut ir::Function, cfg: &mut ControlFlowGraph, is
 
                     // We don't have any pattern expansion for this instruction either.
                     // Try converting it to a library call as a last resort.
-                    if expand_as_libcall(inst, pos.func) {
+                    if expand_as_libcall(inst, pos.func, isa) {
                         pos.set_position(prev_pos);
                         continue;
                     }

lib/codegen/src/settings.rs

@@ -25,6 +25,7 @@ use isa::TargetIsa;
 use std::fmt;
 use std::result;
 use std::vec::Vec;
+use std::str;
 
 /// A string-based configurator for settings groups.
 ///
@@ -360,6 +361,7 @@ mod tests {
              opt_level = \"default\"\n\
              enable_verifier = true\n\
              is_64bit = false\n\
+             call_conv = \"fast\"\n\
              is_pic = false\n\
              return_at_end = false\n\
              avoid_div_traps = false\n\
@@ -367,12 +369,12 @@ mod tests {
              enable_float = true\n\
              enable_simd = true\n\
              enable_atomics = true\n\
-             spiderwasm_prologue_words = 0\n\
+             baldrdash_prologue_words = 0\n\
              allones_funcaddrs = false\n"
         );
         assert_eq!(f.opt_level(), super::OptLevel::Default);
         assert_eq!(f.enable_simd(), true);
-        assert_eq!(f.spiderwasm_prologue_words(), 0);
+        assert_eq!(f.baldrdash_prologue_words(), 0);
     }
 
     #[test]

lib/codegen/src/write.rs

@@ -459,34 +459,34 @@ mod tests {
     #[test]
     fn basic() {
         let mut f = Function::new();
-        assert_eq!(f.to_string(), "function u0:0() system_v {\n}\n");
+        assert_eq!(f.to_string(), "function u0:0() fast {\n}\n");
 
         f.name = ExternalName::testcase("foo");
-        assert_eq!(f.to_string(), "function %foo() system_v {\n}\n");
+        assert_eq!(f.to_string(), "function %foo() fast {\n}\n");
 
         f.create_stack_slot(StackSlotData::new(StackSlotKind::ExplicitSlot, 4));
         assert_eq!(
             f.to_string(),
-            "function %foo() system_v {\n    ss0 = explicit_slot 4\n}\n"
+            "function %foo() fast {\n    ss0 = explicit_slot 4\n}\n"
         );
 
         let ebb = f.dfg.make_ebb();
         f.layout.append_ebb(ebb);
         assert_eq!(
             f.to_string(),
-            "function %foo() system_v {\n    ss0 = explicit_slot 4\n\nebb0:\n}\n"
+            "function %foo() fast {\n    ss0 = explicit_slot 4\n\nebb0:\n}\n"
         );
 
         f.dfg.append_ebb_param(ebb, types::I8);
         assert_eq!(
             f.to_string(),
-            "function %foo() system_v {\n    ss0 = explicit_slot 4\n\nebb0(v0: i8):\n}\n"
+            "function %foo() fast {\n    ss0 = explicit_slot 4\n\nebb0(v0: i8):\n}\n"
         );
 
         f.dfg.append_ebb_param(ebb, types::F32.by(4).unwrap());
         assert_eq!(
             f.to_string(),
-            "function %foo() system_v {\n    ss0 = explicit_slot 4\n\nebb0(v0: i8, v1: f32x4):\n}\n"
+            "function %foo() fast {\n    ss0 = explicit_slot 4\n\nebb0(v0: i8, v1: f32x4):\n}\n"
         );
     }
 }

lib/faerie/src/backend.rs

@@ -23,6 +23,10 @@ impl FaerieBuilder {
     /// Create a new `FaerieBuilder` using the given Cretonne target, that
     /// can be passed to
     /// [`Module::new`](cretonne_module/struct.Module.html#method.new].
+    ///
+    /// Note: To support calls JIT'd functions from Rust or other compiled
+    /// code, it's necessary for the `call_conv` setting in `isa`'s flags
+    /// to match the host platform.
     pub fn new(
         isa: Box<TargetIsa>,
         name: String,

lib/frontend/src/frontend.rs

@@ -596,8 +596,9 @@ mod tests {
     use Variable;
     use cretonne_codegen::entity::EntityRef;
     use cretonne_codegen::ir::types::*;
-    use cretonne_codegen::ir::{AbiParam, CallConv, ExternalName, Function, InstBuilder, Signature};
+    use cretonne_codegen::ir::{AbiParam, ExternalName, Function, InstBuilder, Signature};
     use cretonne_codegen::settings;
+    use cretonne_codegen::settings::CallConv;
     use cretonne_codegen::verifier::verify_function;
     use frontend::{FunctionBuilder, FunctionBuilderContext};
 

lib/frontend/src/lib.rs

@@ -36,9 +36,9 @@
 //! extern crate cretonne_frontend;
 //!
 //! use cretonne_codegen::entity::EntityRef;
-//! use cretonne_codegen::ir::{ExternalName, CallConv, Function, Signature, AbiParam, InstBuilder};
+//! use cretonne_codegen::ir::{ExternalName, Function, Signature, AbiParam, InstBuilder};
 //! use cretonne_codegen::ir::types::*;
-//! use cretonne_codegen::settings;
+//! use cretonne_codegen::settings::{self, CallConv};
 //! use cretonne_frontend::{FunctionBuilderContext, FunctionBuilder, Variable};
 //! use cretonne_codegen::verifier::verify_function;
 //!

lib/native/src/lib.rs

@@ -34,12 +34,21 @@ use raw_cpuid::CpuId;
 pub fn builders() -> Result<(settings::Builder, isa::Builder), &'static str> {
     let mut flag_builder = settings::builder();
 
-    // TODO: Add RISC-V support once Rust supports it.
+    if cfg!(unix) {
+        flag_builder.set("call_conv", "system_v").unwrap();
+    } else if cfg!(windows) {
+        flag_builder.set("call_conv", "fastcall").unwrap();
+    } else {
+        return Err("unrecognized environment");
+    }
 
     if cfg!(target_pointer_width = "64") {
         flag_builder.enable("is_64bit").unwrap();
+    } else if !cfg!(target_pointer_width = "32") {
+        return Err("unrecognized pointer size");
     }
 
+    // TODO: Add RISC-V support once Rust supports it.
     let name = if cfg!(any(target_arch = "x86", target_arch = "x86_64")) {
         "x86"
     } else if cfg!(target_arch = "arm") {

lib/reader/src/parser.rs

@@ -6,7 +6,7 @@ use cretonne_codegen::ir::entities::AnyEntity;
 use cretonne_codegen::ir::immediates::{Ieee32, Ieee64, Imm64, Offset32, Uimm32};
 use cretonne_codegen::ir::instructions::{InstructionData, InstructionFormat, VariableArgs};
 use cretonne_codegen::ir::types::VOID;
-use cretonne_codegen::ir::{AbiParam, ArgumentExtension, ArgumentLoc, CallConv, Ebb, ExtFuncData,
+use cretonne_codegen::ir::{AbiParam, ArgumentExtension, ArgumentLoc, Ebb, ExtFuncData,
                            ExternalName, FuncRef, Function, GlobalVar, GlobalVarData, Heap,
                            HeapBase, HeapData, HeapStyle, JumpTable, JumpTableData, MemFlags,
                            Opcode, SigRef, Signature, StackSlot, StackSlotData, StackSlotKind,
@@ -14,6 +14,7 @@ use cretonne_codegen::ir::{AbiParam, ArgumentExtension, ArgumentLoc, CallConv, E
 use cretonne_codegen::isa::{self, Encoding, RegUnit, TargetIsa};
 use cretonne_codegen::packed_option::ReservedValue;
 use cretonne_codegen::{settings, timing};
+use cretonne_codegen::settings::CallConv;
 use error::{Error, Location, Result};
 use isaspec;
 use lexer::{self, Lexer, Token};
@@ -188,7 +189,7 @@ impl<'a> Context<'a> {
     fn add_sig(&mut self, sig: SigRef, data: Signature, loc: &Location) -> Result<()> {
         while self.function.dfg.signatures.next_key().index() <= sig.index() {
             self.function.import_signature(
-                Signature::new(CallConv::SystemV),
+                Signature::new(CallConv::Fast),
             );
         }
         self.function.dfg.signatures[sig] = data;
@@ -862,8 +863,8 @@ impl<'a> Parser<'a> {
     // signature ::=  * "(" [paramlist] ")" ["->" retlist] [callconv]
     //
     fn parse_signature(&mut self, unique_isa: Option<&TargetIsa>) -> Result<Signature> {
-        // Calling convention defaults to `system_v`, but can be changed.
+        // Calling convention defaults to `fast`, but can be changed.
-        let mut sig = Signature::new(CallConv::SystemV);
+        let mut sig = Signature::new(CallConv::Fast);
 
         self.match_token(
             Token::LPar,
@@ -2402,7 +2403,8 @@ mod tests {
     use cretonne_codegen::ir::StackSlotKind;
     use cretonne_codegen::ir::entities::AnyEntity;
     use cretonne_codegen::ir::types;
-    use cretonne_codegen::ir::{ArgumentExtension, ArgumentPurpose, CallConv};
+    use cretonne_codegen::ir::{ArgumentExtension, ArgumentPurpose};
+    use cretonne_codegen::settings::CallConv;
     use error::Error;
     use isaspec::IsaSpec;
     use testfile::{Comment, Details};
@@ -2451,19 +2453,19 @@ mod tests {
         assert_eq!(sig.returns.len(), 0);
         assert_eq!(sig.call_conv, CallConv::SystemV);
 
-        let sig2 = Parser::new("(i8 uext, f32, f64, i32 sret) -> i32 sext, f64 spiderwasm")
+        let sig2 = Parser::new("(i8 uext, f32, f64, i32 sret) -> i32 sext, f64 baldrdash")
             .parse_signature(None)
             .unwrap();
         assert_eq!(
             sig2.to_string(),
-            "(i8 uext, f32, f64, i32 sret) -> i32 sext, f64 spiderwasm"
+            "(i8 uext, f32, f64, i32 sret) -> i32 sext, f64 baldrdash"
         );
-        assert_eq!(sig2.call_conv, CallConv::SpiderWASM);
+        assert_eq!(sig2.call_conv, CallConv::Baldrdash);
 
         // Old-style signature without a calling convention.
         assert_eq!(
             Parser::new("()").parse_signature(None).unwrap().to_string(),
-            "() system_v"
+            "() fast"
         );
         assert_eq!(
             Parser::new("() notacc")

lib/umbrella/src/lib.rs

@@ -25,12 +25,12 @@ pub extern crate cretonne_frontend as frontend;
 pub mod prelude {
     pub use codegen;
     pub use codegen::entity::EntityRef;
-    pub use codegen::ir::{AbiParam, InstBuilder, Value, Ebb, Signature, CallConv, Type,
+    pub use codegen::ir::{AbiParam, InstBuilder, Value, Ebb, Signature, Type, JumpTableData,
-                          JumpTableData, MemFlags};
+                          MemFlags};
     pub use codegen::ir::types;
     pub use codegen::ir::condcodes::{IntCC, FloatCC};
     pub use codegen::ir::immediates::{Ieee32, Ieee64};
-    pub use codegen::settings::{self, Configurable};
+    pub use codegen::settings::{self, Configurable, CallConv};
     pub use codegen::isa;
 
     pub use frontend::{FunctionBuilderContext, FunctionBuilder, Variable};

lib/wasm/src/environ/dummy.rs

@@ -271,6 +271,10 @@ impl<'dummy_environment> FuncEnvironment for DummyFuncEnvironment<'dummy_environ
 }
 
 impl<'data> ModuleEnvironment<'data> for DummyEnvironment {
+    fn flags(&self) -> &settings::Flags {
+        &self.info.flags
+    }
+
     fn get_func_name(&self, func_index: FunctionIndex) -> ir::ExternalName {
         get_func_name(func_index)
     }

lib/wasm/src/environ/spec.rs

@@ -160,6 +160,9 @@ pub trait FuncEnvironment {
 /// [`translate_module`](fn.translate_module.html) function. These methods should not be called
 /// by the user, they are only for `cretonne-wasm` internal use.
 pub trait ModuleEnvironment<'data> {
+    /// Get the flags for the current compilation.
+    fn flags(&self) -> &Flags;
+
     /// Return the name for the given function index.
     fn get_func_name(&self, func_index: FunctionIndex) -> ir::ExternalName;
 

lib/wasm/src/sections_translator.rs

@@ -7,7 +7,7 @@
 //! The special case of the initialize expressions for table elements offsets or global variables
 //! is handled, according to the semantics of WebAssembly, to only specific expressions that are
 //! interpreted on the fly.
-use cretonne_codegen::ir::{self, AbiParam, CallConv, Signature};
+use cretonne_codegen::ir::{self, AbiParam, Signature};
 use environ::ModuleEnvironment;
 use std::str::from_utf8;
 use std::string::String;
@@ -35,7 +35,7 @@ pub fn parse_function_signatures(
                                               ref params,
                                               ref returns,
                                           }) => {
-                let mut sig = Signature::new(CallConv::SystemV);
+                let mut sig = Signature::new(environ.flags().call_conv());
                 sig.params.extend(params.iter().map(|ty| {
                     let cret_arg: ir::Type = type_to_type(ty).expect(
                         "only numeric types are supported in function signatures",