llvm/test/CodeGen/X86/vec_unsafe-fp-math.ll
Sanjay Patel 52af82df95 Allow vector fsub ops with constants to get the same optimizations as scalars.
This problem is bigger than just fsub, but this is the minimum fix to solve
fneg for PR20556 ( http://llvm.org/bugs/show_bug.cgi?id=20556 ), and we solve
zero subtraction with the same change.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217286 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-05 22:26:22 +00:00

24 lines
680 B
LLVM

; RUN: llc < %s -enable-unsafe-fp-math -mtriple=x86_64-unknown-unknown -mcpu=corei7 | FileCheck %s
; Make sure that vectors get the same benefits as scalars when using unsafe-fp-math.
; Subtracting zero is free.
define <4 x float> @vec_fsub_zero(<4 x float> %x) {
; CHECK-LABEL: vec_fsub_zero:
; CHECK-NOT: subps
; CHECK-NOT: xorps
; CHECK: retq
%sub = fsub <4 x float> %x, zeroinitializer
ret <4 x float> %sub
}
; Negating doesn't require subtraction.
define <4 x float> @vec_fneg(<4 x float> %x) {
; CHECK-LABEL: vec_fneg:
; CHECK: xorps {{.*}}LCP{{.*}}, %xmm0
; CHECK-NOT: subps
; CHECK-NEXT: retq
%sub = fsub <4 x float> zeroinitializer, %x
ret <4 x float> %sub
}