GlobalISel: Use the original flags when lowering fneg to fsub

This was ignoring the flag on fneg, and using the source instruction's
flags. Also fixes tests missing from r358702.

Note the expansion itself isn't correct without nnan, but that should
be fixed separately.

llvm-svn: 363637

1 files changed, 31 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/AMDGPU/GlobalISel/irtranslator-fast-math-flags.ll b/llvm/test/CodeGen/AMDGPU/GlobalISel/irtranslator-fast-math-flags.ll
new file mode 100644
index 00000000000..dc660bfca29
--- /dev/null
+++ b/llvm/test/CodeGen/AMDGPU/GlobalISel/irtranslator-fast-math-flags.ll
@@ -0,0 +1,31 @@
+; RUN: llc -march=amdgcn -mcpu=fiji -O0 -stop-after=irtranslator -global-isel %s -o - | FileCheck %s
+
+; Check flags are preserved for a regular instruction.
+; CHECK-LABEL: name: fadd_nnan
+; CHECK: nnan G_FADD
+define amdgpu_kernel void @fadd_nnan(float %arg0, float %arg1) {
+  %res = fadd nnan float %arg0, %arg1
+  store float %res, float addrspace(1)* undef
+  ret void
+}
+
+; Check flags are preserved for a specially handled intrinsic
+; CHECK-LABEL: name: fma_fast
+; CHECK: nnan ninf nsz arcp contract afn reassoc G_FMA
+define amdgpu_kernel void @fma_fast(float %arg0, float %arg1, float %arg2) {
+  %res = call fast float @llvm.fma.f32(float %arg0, float %arg1, float %arg2)
+  store float %res, float addrspace(1)* undef
+  ret void
+}
+
+; Check flags are preserved for an arbitrarry target intrinsic
+; CHECK-LABEL: name: rcp_nsz
+; CHECK: = nsz G_INTRINSIC intrinsic(@llvm.amdgcn.rcp), %8(s32)
+define amdgpu_kernel void @rcp_nsz(float %arg0) {
+  %res = call nsz float @llvm.amdgcn.rcp.f32 (float %arg0)
+  store float %res, float addrspace(1)* undef
+  ret void
+}
+
+declare float @llvm.fma.f32(float, float, float)
+declare float @llvm.amdgcn.rcp.f32(float)