fdiv.ll
3.15 KB
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; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc < %s -mtriple=x86_64-unknown-unknown -enable-unsafe-fp-math | FileCheck %s
define double @exact(double %x) {
; Exact division by a constant converted to multiplication.
; CHECK-LABEL: exact:
; CHECK: # %bb.0:
; CHECK-NEXT: mulsd {{.*}}(%rip), %xmm0
; CHECK-NEXT: retq
%div = fdiv double %x, 2.0
ret double %div
}
define double @inexact(double %x) {
; Inexact division by a constant converted to multiplication.
; CHECK-LABEL: inexact:
; CHECK: # %bb.0:
; CHECK-NEXT: mulsd {{.*}}(%rip), %xmm0
; CHECK-NEXT: retq
%div = fdiv double %x, 0x41DFFFFFFFC00000
ret double %div
}
define double @funky(double %x) {
; No conversion to multiplication if too funky.
; CHECK-LABEL: funky:
; CHECK: # %bb.0:
; CHECK-NEXT: xorpd %xmm1, %xmm1
; CHECK-NEXT: divsd %xmm1, %xmm0
; CHECK-NEXT: retq
%div = fdiv double %x, 0.0
ret double %div
}
define double @denormal1(double %x) {
; Don't generate multiplication by a denormal.
; CHECK-LABEL: denormal1:
; CHECK: # %bb.0:
; CHECK-NEXT: divsd {{.*}}(%rip), %xmm0
; CHECK-NEXT: retq
%div = fdiv double %x, 0x7FD0000000000001
ret double %div
}
define double @denormal2(double %x) {
; Don't generate multiplication by a denormal.
; CHECK-LABEL: denormal2:
; CHECK: # %bb.0:
; CHECK-NEXT: divsd {{.*}}(%rip), %xmm0
; CHECK-NEXT: retq
%div = fdiv double %x, 0x7FEFFFFFFFFFFFFF
ret double %div
}
; Deleting the negates does not require unsafe-fp-math.
define float @double_negative(float %x, float %y) #0 {
; CHECK-LABEL: double_negative:
; CHECK: # %bb.0:
; CHECK-NEXT: divss %xmm1, %xmm0
; CHECK-NEXT: retq
%neg1 = fsub float -0.0, %x
%neg2 = fsub float -0.0, %y
%div = fdiv float %neg1, %neg2
ret float %div
}
define <4 x float> @double_negative_vector(<4 x float> %x, <4 x float> %y) #0 {
; CHECK-LABEL: double_negative_vector:
; CHECK: # %bb.0:
; CHECK-NEXT: divps %xmm1, %xmm0
; CHECK-NEXT: retq
%neg1 = fsub <4 x float> <float -0.0, float -0.0, float -0.0, float -0.0>, %x
%neg2 = fsub <4 x float> <float -0.0, float -0.0, float -0.0, float -0.0>, %y
%div = fdiv <4 x float> %neg1, %neg2
ret <4 x float> %div
}
; This test used to fail, depending on how llc was built (e.g. using
; clang/gcc), due to order of argument evaluation not being well defined. We
; ended up hitting llvm_unreachable in getNegatedExpression when building with
; gcc. Just make sure that we get a deterministic result.
define float @fdiv_fneg_combine(float %a0, float %a1, float %a2) #0 {
; CHECK-LABEL: fdiv_fneg_combine:
; CHECK: # %bb.0:
; CHECK-NEXT: movaps %xmm0, %xmm3
; CHECK-NEXT: subss %xmm1, %xmm3
; CHECK-NEXT: subss %xmm0, %xmm1
; CHECK-NEXT: mulss %xmm2, %xmm1
; CHECK-NEXT: subss %xmm2, %xmm3
; CHECK-NEXT: divss %xmm3, %xmm1
; CHECK-NEXT: movaps %xmm1, %xmm0
; CHECK-NEXT: retq
%sub1 = fsub fast float %a0, %a1
%mul2 = fmul fast float %sub1, %a2
%neg = fneg fast float %a0
%add3 = fadd fast float %a1, %neg
%sub4 = fadd fast float %add3, %a2
%div5 = fdiv fast float %mul2, %sub4
ret float %div5
}
attributes #0 = { "unsafe-fp-math"="false" }