Allow speculating llvm.sqrt, fma and fmuladd

This doesn't set errno, so this should be OK.
Also update the documentation to explicitly state
that errno are not set.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200501 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 58 insertions, 0 deletions

diff --git a/test/Transforms/SimplifyCFG/speculate-math.ll b/test/Transforms/SimplifyCFG/speculate-math.ll
new file mode 100644
index 0000000000..fa7976d068
--- /dev/null
+++ b/test/Transforms/SimplifyCFG/speculate-math.ll
@@ -0,0 +1,58 @@
+; RUN: opt -S -simplifycfg -phi-node-folding-threshold=2 < %s | FileCheck %s
+
+declare float @llvm.sqrt.f32(float) nounwind readonly
+declare float @llvm.fma.f32(float, float, float) nounwind readonly
+declare float @llvm.fmuladd.f32(float, float, float) nounwind readonly
+
+; CHECK-LABEL: @sqrt_test(
+; CHECK: select
+define void @sqrt_test(float addrspace(1)* noalias nocapture %out, float %a) nounwind {
+entry:
+  %cmp.i = fcmp olt float %a, 0.000000e+00
+  br i1 %cmp.i, label %test_sqrt.exit, label %cond.else.i
+
+cond.else.i:                                      ; preds = %entry
+  %0 = tail call float @llvm.sqrt.f32(float %a) nounwind readnone
+  br label %test_sqrt.exit
+
+test_sqrt.exit:                                   ; preds = %cond.else.i, %entry
+  %cond.i = phi float [ %0, %cond.else.i ], [ 0x7FF8000000000000, %entry ]
+  store float %cond.i, float addrspace(1)* %out, align 4
+  ret void
+}
+
+
+; CHECK-LABEL: @fma_test(
+; CHECK: select
+define void @fma_test(float addrspace(1)* noalias nocapture %out, float %a, float %b, float %c) nounwind {
+entry:
+  %cmp.i = fcmp olt float %a, 0.000000e+00
+  br i1 %cmp.i, label %test_fma.exit, label %cond.else.i
+
+cond.else.i:                                      ; preds = %entry
+  %0 = tail call float @llvm.fma.f32(float %a, float %b, float %c) nounwind readnone
+  br label %test_fma.exit
+
+test_fma.exit:                                   ; preds = %cond.else.i, %entry
+  %cond.i = phi float [ %0, %cond.else.i ], [ 0x7FF8000000000000, %entry ]
+  store float %cond.i, float addrspace(1)* %out, align 4
+  ret void
+}
+
+; CHECK-LABEL: @fmuladd_test(
+; CHECK: select
+define void @fmuladd_test(float addrspace(1)* noalias nocapture %out, float %a, float %b, float %c) nounwind {
+entry:
+  %cmp.i = fcmp olt float %a, 0.000000e+00
+  br i1 %cmp.i, label %test_fmuladd.exit, label %cond.else.i
+
+cond.else.i:                                      ; preds = %entry
+  %0 = tail call float @llvm.fmuladd.f32(float %a, float %b, float %c) nounwind readnone
+  br label %test_fmuladd.exit
+
+test_fmuladd.exit:                                   ; preds = %cond.else.i, %entry
+  %cond.i = phi float [ %0, %cond.else.i ], [ 0x7FF8000000000000, %entry ]
+  store float %cond.i, float addrspace(1)* %out, align 4
+  ret void
+}
+