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x64: emit_cmp: use x64_test for comparisons with 0 (#6086)

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* x64: emit_cmp: use x64_test for comparisons with 0

See #5869

* fixup! x64: emit_cmp: use x64_test for comparisons with 0
This commit is contained in:
Maja Kądziołka
2023-03-27 17:38:48 +02:00
committed by GitHub
parent dd9804514d
commit db07988ccb
3 changed files with 196 additions and 11 deletions
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17
cranelift/codegen/src/isa/x64/inst.isle
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@@ -4375,9 +4375,20 @@
(let ((size OperandSize (raw_operand_size_of_type ty)))
(icmp_cond_result (x64_cmp size a b) (intcc_reverse cc))))
;; Special case: use the test instruction for comparisons with 0.
(rule 2 (emit_cmp cc a @ (value_type ty) (u64_from_iconst 0))
(let ((size OperandSize (raw_operand_size_of_type ty))
(a Gpr (put_in_reg a)))
(icmp_cond_result (x64_test size a a) cc)))
(rule 3 (emit_cmp cc (u64_from_iconst 0) b @ (value_type ty))
(let ((size OperandSize (raw_operand_size_of_type ty))
(b Gpr (put_in_reg b)))
(icmp_cond_result (x64_test size b b) (intcc_reverse cc))))
;; For I128 values (held in two GPRs), the instruction sequences depend on what
;; kind of condition is tested.
(rule 3 (emit_cmp (IntCC.Equal) a @ (value_type $I128) b)
(rule 5 (emit_cmp (IntCC.Equal) a @ (value_type $I128) b)
(let ((a_lo Gpr (value_regs_get_gpr a 0))
(a_hi Gpr (value_regs_get_gpr a 1))
(b_lo Gpr (value_regs_get_gpr b 0))
@@ -4398,7 +4409,7 @@
(x64_test (OperandSize.Size64) (RegMemImm.Imm 1) cmp)
(CC.NZ))))
(rule 3 (emit_cmp (IntCC.NotEqual) a @ (value_type $I128) b)
(rule 5 (emit_cmp (IntCC.NotEqual) a @ (value_type $I128) b)
(let ((a_lo Gpr (value_regs_get_gpr a 0))
(a_hi Gpr (value_regs_get_gpr a 1))
(b_lo Gpr (value_regs_get_gpr b 0))
@@ -4413,7 +4424,7 @@
;; Result = (a_hi <> b_hi) ||
;; (a_hi == b_hi && a_lo <> b_lo)
(rule 2 (emit_cmp cc a @ (value_type $I128) b)
(rule 4 (emit_cmp cc a @ (value_type $I128) b)
(let ((a_lo Gpr (value_regs_get_gpr a 0))
(a_hi Gpr (value_regs_get_gpr a 1))
(b_lo Gpr (value_regs_get_gpr b 0))