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Fixes #600: Add a SIB byte when encoding a non-indexed load/store into r12/rsp;

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Memory access instructions which took the GPR_ZERO_DEREF_SAFE register
class (that was removed in #600) should check for the need of either an
offset (r13/rbp) or the SIB byte (r12/rsp). Some load/store instructions
would already take an index, thus already contain the SIB byte in this
case (see instructions which have a comment telling that the else branch
already contains an SIB byte). Non-indexed memory accesses lacked the
SIB byte check, which this patch adds.
This commit is contained in:
Benjamin Bouvier
2018-11-13 19:04:13 +01:00
committed by Dan Gohman
parent f6617afcdd
commit b170b74b65
2 changed files with 44 additions and 8 deletions
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33
lib/codegen/meta-python/isa/x86/recipes.py
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@@ -806,13 +806,16 @@ st = TailRecipe(
'st', Store, base_size=1, ins=(GPR, GPR), outs=(),
instp=IsEqual(Store.offset, 0),
clobbers_flags=False,
compute_size="size_plus_maybe_offset_for_in_reg_1",
compute_size="size_plus_maybe_sib_or_offset_for_in_reg_1",
emit='''
if !flags.notrap() {
sink.trap(TrapCode::HeapOutOfBounds, func.srclocs[inst]);
}
PUT_OP(bits, rex2(in_reg1, in_reg0), sink);
if needs_offset(in_reg1) {
if needs_sib_byte(in_reg1) {
modrm_sib(in_reg0, sink);
sib_noindex(in_reg1, sink);
} else if needs_offset(in_reg1) {
modrm_disp8(in_reg1, in_reg0, sink);
sink.put1(0);
} else {
@@ -833,6 +836,7 @@ stWithIndex = TailRecipe(
sink.trap(TrapCode::HeapOutOfBounds, func.srclocs[inst]);
}
PUT_OP(bits, rex3(in_reg1, in_reg0, in_reg2), sink);
// The else branch always inserts an SIB byte.
if needs_offset(in_reg1) {
modrm_sib_disp8(in_reg0, sink);
sib(0, in_reg2, in_reg1, sink);
@@ -872,6 +876,7 @@ stWithIndex_abcd = TailRecipe(
sink.trap(TrapCode::HeapOutOfBounds, func.srclocs[inst]);
}
PUT_OP(bits, rex3(in_reg1, in_reg0, in_reg2), sink);
// The else branch always inserts an SIB byte.
if needs_offset(in_reg1) {
modrm_sib_disp8(in_reg0, sink);
sib(0, in_reg2, in_reg1, sink);
@@ -887,13 +892,16 @@ fst = TailRecipe(
'fst', Store, base_size=1, ins=(FPR, GPR), outs=(),
instp=IsEqual(Store.offset, 0),
clobbers_flags=False,
compute_size="size_plus_maybe_offset_for_in_reg_1",
compute_size="size_plus_maybe_sib_or_offset_for_in_reg_1",
emit='''
if !flags.notrap() {
sink.trap(TrapCode::HeapOutOfBounds, func.srclocs[inst]);
}
PUT_OP(bits, rex2(in_reg1, in_reg0), sink);
if needs_offset(in_reg1) {
if needs_sib_byte(in_reg1) {
modrm_sib(in_reg0, sink);
sib_noindex(in_reg1, sink);
} else if needs_offset(in_reg1) {
modrm_disp8(in_reg1, in_reg0, sink);
sink.put1(0);
} else {
@@ -912,6 +920,7 @@ fstWithIndex = TailRecipe(
sink.trap(TrapCode::HeapOutOfBounds, func.srclocs[inst]);
}
PUT_OP(bits, rex3(in_reg1, in_reg0, in_reg2), sink);
// The else branch always inserts an SIB byte.
if needs_offset(in_reg1) {
modrm_sib_disp8(in_reg0, sink);
sib(0, in_reg2, in_reg1, sink);
@@ -1210,13 +1219,16 @@ ld = TailRecipe(
'ld', Load, base_size=1, ins=(GPR), outs=(GPR),
instp=IsEqual(Load.offset, 0),
clobbers_flags=False,
compute_size="size_plus_maybe_offset_for_in_reg_0",
compute_size="size_plus_maybe_sib_or_offset_for_in_reg_0",
emit='''
if !flags.notrap() {
sink.trap(TrapCode::HeapOutOfBounds, func.srclocs[inst]);
}
PUT_OP(bits, rex2(in_reg0, out_reg0), sink);
if needs_offset(in_reg0) {
if needs_sib_byte(in_reg0) {
modrm_sib(out_reg0, sink);
sib_noindex(in_reg0, sink);
} else if needs_offset(in_reg0) {
modrm_disp8(in_reg0, out_reg0, sink);
sink.put1(0);
} else {
@@ -1237,6 +1249,7 @@ ldWithIndex = TailRecipe(
sink.trap(TrapCode::HeapOutOfBounds, func.srclocs[inst]);
}
PUT_OP(bits, rex3(in_reg0, out_reg0, in_reg1), sink);
// The else branch always inserts an SIB byte.
if needs_offset(in_reg0) {
modrm_sib_disp8(out_reg0, sink);
sib(0, in_reg1, in_reg0, sink);
@@ -1252,13 +1265,16 @@ fld = TailRecipe(
'fld', Load, base_size=1, ins=(GPR), outs=(FPR),
instp=IsEqual(Load.offset, 0),
clobbers_flags=False,
compute_size="size_plus_maybe_offset_for_in_reg_0",
compute_size="size_plus_maybe_sib_or_offset_for_in_reg_0",
emit='''
if !flags.notrap() {
sink.trap(TrapCode::HeapOutOfBounds, func.srclocs[inst]);
}
PUT_OP(bits, rex2(in_reg0, out_reg0), sink);
if needs_offset(in_reg0) {
if needs_sib_byte(in_reg0) {
modrm_sib(out_reg0, sink);
sib_noindex(in_reg0, sink);
} else if needs_offset(in_reg0) {
modrm_disp8(in_reg0, out_reg0, sink);
sink.put1(0);
} else {
@@ -1279,6 +1295,7 @@ fldWithIndex = TailRecipe(
sink.trap(TrapCode::HeapOutOfBounds, func.srclocs[inst]);
}
PUT_OP(bits, rex3(in_reg0, out_reg0, in_reg1), sink);
// The else branch always inserts an SIB byte.
if needs_offset(in_reg0) {
modrm_sib_disp8(out_reg0, sink);
sib(0, in_reg1, in_reg0, sink);