From: Craig Topper <craig.topper@intel.com>
Date: Mon, 6 May 2019 22:04:26 +0000 (+0000)
Subject: [X86] Add more test cases for fast-isel handling of fneg.
X-Git-Tag: llvmorg-10-init~6163
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=77e69d88508b7778690d9cf87297c5a09413cfb4;p=platform%2Fupstream%2Fllvm.git

[X86] Add more test cases for fast-isel handling of fneg.

The fneg double case is falling back to a subsd in 32-bit mode if you write a test that doesn't trigger a fast-isel abort on the return value.

The subsd lowering has different behavior with respect to nans than using an xor. This is inconsisent with what we would do in SelectionDAG
and can lead to differences between -O0 and -O2.

llvm-svn: 360088
---

diff --git a/llvm/test/CodeGen/X86/fast-isel-fneg.ll b/llvm/test/CodeGen/X86/fast-isel-fneg.ll
index 0c2ce6d..09ef343 100644
--- a/llvm/test/CodeGen/X86/fast-isel-fneg.ll
+++ b/llvm/test/CodeGen/X86/fast-isel-fneg.ll
@@ -1,6 +1,6 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
-; RUN: llc < %s -fast-isel -fast-isel-abort=1 -mtriple=x86_64-apple-darwin10 | FileCheck %s
-; RUN: llc < %s -fast-isel -mtriple=i686-- -mattr=+sse2 | FileCheck --check-prefix=SSE2 %s
+; RUN: llc < %s -fast-isel -fast-isel-abort=3 -mtriple=x86_64-apple-darwin10 | FileCheck %s
+; RUN: llc < %s -fast-isel -fast-isel-abort=1 -mtriple=i686-- -mattr=+sse2 | FileCheck --check-prefix=SSE2 %s
 
 define double @doo(double %x) nounwind {
 ; CHECK-LABEL: doo:
@@ -48,3 +48,54 @@ define float @foo(float %x) nounwind {
   %y = fsub float -0.0, %x
   ret float %y
 }
+
+define void @goo(double* %x, double* %y) nounwind {
+; CHECK-LABEL: goo:
+; CHECK:       ## %bb.0:
+; CHECK-NEXT:    movq {{.*#+}} xmm0 = mem[0],zero
+; CHECK-NEXT:    movq %xmm0, %rax
+; CHECK-NEXT:    movabsq $-9223372036854775808, %rcx ## imm = 0x8000000000000000
+; CHECK-NEXT:    xorq %rax, %rcx
+; CHECK-NEXT:    movq %rcx, %xmm0
+; CHECK-NEXT:    movq %xmm0, (%rsi)
+; CHECK-NEXT:    retq
+;
+; SSE2-LABEL: goo:
+; SSE2:       # %bb.0:
+; SSE2-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; SSE2-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; SSE2-NEXT:    movsd {{.*#+}} xmm0 = mem[0],zero
+; SSE2-NEXT:    subsd (%ecx), %xmm0
+; SSE2-NEXT:    movsd %xmm0, (%eax)
+; SSE2-NEXT:    retl
+  %a = load double, double* %x
+  %b = fsub double -0.0, %a
+  store double %b, double* %y
+  ret void
+}
+
+define void @loo(float* %x, float* %y) nounwind {
+; CHECK-LABEL: loo:
+; CHECK:       ## %bb.0:
+; CHECK-NEXT:    movd {{.*#+}} xmm0 = mem[0],zero,zero,zero
+; CHECK-NEXT:    movd %xmm0, %eax
+; CHECK-NEXT:    xorl $2147483648, %eax ## imm = 0x80000000
+; CHECK-NEXT:    movd %eax, %xmm0
+; CHECK-NEXT:    movd %xmm0, (%rsi)
+; CHECK-NEXT:    retq
+;
+; SSE2-LABEL: loo:
+; SSE2:       # %bb.0:
+; SSE2-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; SSE2-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; SSE2-NEXT:    movd {{.*#+}} xmm0 = mem[0],zero,zero,zero
+; SSE2-NEXT:    movd %xmm0, %ecx
+; SSE2-NEXT:    xorl $2147483648, %ecx # imm = 0x80000000
+; SSE2-NEXT:    movd %ecx, %xmm0
+; SSE2-NEXT:    movd %xmm0, (%eax)
+; SSE2-NEXT:    retl
+  %a = load float, float* %x
+  %b = fsub float -0.0, %a
+  store float %b, float* %y
+  ret void
+}