Added a slew of SimplifyInstruction floating-point optimizations, many of which take advantage of fast-math flags. Test cases included.

  fsub X, +0 ==> X
  fsub X, -0 ==> X, when we know X is not -0
  fsub +/-0.0, (fsub -0.0, X) ==> X
  fsub nsz +/-0.0, (fsub +/-0.0, X) ==> X
  fsub nnan ninf X, X ==> 0.0
  fadd nsz X, 0 ==> X
  fadd [nnan ninf] X, (fsub [nnan ninf] 0, X) ==> 0
    where nnan and ninf have to occur at least once somewhere in this expression
  fmul X, 1.0 ==> X



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169940 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 14 insertions, 0 deletions

diff --git a/include/llvm/Analysis/InstructionSimplify.h b/include/llvm/Analysis/InstructionSimplify.h
index e9b72a2fa7..721f0ddd2e 100644
--- a/include/llvm/Analysis/InstructionSimplify.h
+++ b/include/llvm/Analysis/InstructionSimplify.h
@@ -44,6 +44,20 @@ namespace llvm {
                          const TargetLibraryInfo *TLI = 0,
                          const DominatorTree *DT = 0);
 
+  /// Given operands for an FAdd, see if we can fold the result.  If not, this
+  /// returns null.
+  Value *SimplifyFAddInst(Value *LHS, Value *RHS, FastMathFlags FMF,
+                         const DataLayout *TD = 0,
+                         const TargetLibraryInfo *TLI = 0,
+                         const DominatorTree *DT = 0);
+
+  /// Given operands for an FSub, see if we can fold the result.  If not, this
+  /// returns null.
+  Value *SimplifyFSubInst(Value *LHS, Value *RHS, FastMathFlags FMF,
+                         const DataLayout *TD = 0,
+                         const TargetLibraryInfo *TLI = 0,
+                         const DominatorTree *DT = 0);
+
   /// Given operands for an FMul, see if we can fold the result.  If not, this
   /// returns null.
   Value *SimplifyFMulInst(Value *LHS, Value *RHS,