Add -ffp-contract = { fast | on | off } command line option support.

This flag sets the 'fp-contract' mode, which controls the formation of fused
floating point operations. Available modes are:

- Fast: Form fused operations anywhere. 
- On: Form fused operations where allowed by FP_CONTRACT. This is the default
      mode.
- Off: Don't form fused operations (in future this may be relaxed to forming
       fused operations where it can be proved that the result won't be
       affected).

Currently clang doesn't support the FP_CONTRACT pragma, so the 'On' and 'Off'
modes are equivalent.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159794 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 8 insertions, 0 deletions

diff --git a/test/CodeGen/fp-contract.c b/test/CodeGen/fp-contract.c
new file mode 100644
index 0000000000..c048d69586
--- /dev/null
+++ b/test/CodeGen/fp-contract.c
@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 -O3 -ffp-contract=fast -triple=powerpc-apple-darwin10 -S -o - %s | FileCheck %s
+
+float fma_test1(float a, float b, float c) {
+// CHECK: fmadds
+  float x = a * b;
+  float y = x + c;
+  return y;
+}