[IR] Add AllowContract to FastMathFlags

-ffp-contract=fast does not currently work with LTO because it's passed as a
TargetOption to the backend rather than in the IR. This adds it to
FastMathFlags.

This is toward fixing PR25721

Differential Revision: https://reviews.llvm.org/D31164

llvm-svn: 298939

2 files changed, 14 insertions, 0 deletions

diff --git a/llvm/test/Assembler/fast-math-flags.ll b/llvm/test/Assembler/fast-math-flags.ll
index f0d3ecc761d..4ef3607e1d0 100644
--- a/llvm/test/Assembler/fast-math-flags.ll
+++ b/llvm/test/Assembler/fast-math-flags.ll
@@ -74,6 +74,18 @@ entry:
   ret float %e
 }
 
+; CHECK: @contract(
+define float @contract(float %x, float %y) {
+entry:
+; CHECK: %a = fsub contract float %x, %y
+  %a = fsub contract float %x, %y
+; CHECK: %b = fadd contract float %x, %y
+  %b = fadd contract float %x, %y
+; CHECK: %c = fmul contract float %a, %b
+  %c = fmul contract float %a, %b
+  ret float %c
+}
+
 ; CHECK: no_nan_inf
 define float @no_nan_inf(float %x, float %y) {
 entry:
diff --git a/llvm/test/Bitcode/compatibility.ll b/llvm/test/Bitcode/compatibility.ll
index f1a883e53ad..b1f52bbe059 100644
--- a/llvm/test/Bitcode/compatibility.ll
+++ b/llvm/test/Bitcode/compatibility.ll
@@ -760,6 +760,8 @@ define void @fastmathflags(float %op1, float %op2) {
   ; CHECK: %f.nsz = fadd nsz float %op1, %op2
   %f.arcp = fadd arcp float %op1, %op2
   ; CHECK: %f.arcp = fadd arcp float %op1, %op2
+  %f.contract = fadd contract float %op1, %op2
+  ; CHECK: %f.contract = fadd contract float %op1, %op2
   %f.fast = fadd fast float %op1, %op2
   ; CHECK: %f.fast = fadd fast float %op1, %op2
   ret void