commit a4f42f2cfdf83c6a8e44728614335330a7dd24d2
author Sanjay Patel <spatel@rotateright.com> Thu Mar 15 14:29:27 2018 +0000
committer Sanjay Patel <spatel@rotateright.com> Thu Mar 15 14:29:27 2018 +0000
tree ee72e76a9286b8aba6e14d52af9d22e85e6c24f3
parent 8f063d0c70dbd3aea79ae16a2d961bb133d2a17d

[PatternMatch, InstSimplify] allow undef elements when matching any vector FP zero

This matcher implementation appears to be slightly more efficient than 
the generic constant check that it is replacing because every use was 
for matching FP patterns, but the previous code would check int and 
pointer type nulls too. 

llvm-svn: 327627

llvm/lib/Analysis/InstructionSimplify.cpp

diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index 773c3ec..5e43cb7 100644
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -4175,8 +4175,8 @@
   // X = -0.0: ( 0.0 - (-0.0)) + (-0.0) == ( 0.0) + (-0.0) == 0.0
   // X =  0.0: (-0.0 - ( 0.0)) + ( 0.0) == (-0.0) + ( 0.0) == 0.0
   // X =  0.0: ( 0.0 - ( 0.0)) + ( 0.0) == ( 0.0) + ( 0.0) == 0.0
-  if (FMF.noNaNs() && (match(Op0, m_FSub(m_AnyZero(), m_Specific(Op1))) ||
-                       match(Op1, m_FSub(m_AnyZero(), m_Specific(Op0)))))
+  if (FMF.noNaNs() && (match(Op0, m_FSub(m_AnyZeroFP(), m_Specific(Op1))) ||
+                       match(Op1, m_FSub(m_AnyZeroFP(), m_Specific(Op0)))))
     return ConstantFP::getNullValue(Op0->getType());
 
   return nullptr;
@@ -4207,8 +4207,8 @@
     return X;
 
   // fsub 0.0, (fsub 0.0, X) ==> X if signed zeros are ignored.
-  if (FMF.noSignedZeros() && match(Op0, m_AnyZero()) &&
-      match(Op1, m_FSub(m_AnyZero(), m_Value(X))))
+  if (FMF.noSignedZeros() && match(Op0, m_AnyZeroFP()) &&
+      match(Op1, m_FSub(m_AnyZeroFP(), m_Value(X))))
     return X;
 
   // fsub nnan x, x ==> 0.0
@@ -4232,8 +4232,8 @@
     return Op0;
 
   // fmul nnan nsz X, 0 ==> 0
-  if (FMF.noNaNs() && FMF.noSignedZeros() && match(Op1, m_AnyZero()))
-    return Op1;
+  if (FMF.noNaNs() && FMF.noSignedZeros() && match(Op1, m_AnyZeroFP()))
+    return ConstantFP::getNullValue(Op0->getType());
 
   // sqrt(X) * sqrt(X) --> X
   Value *X;
@@ -4275,8 +4275,8 @@
   // 0 / X -> 0
   // Requires that NaNs are off (X could be zero) and signed zeroes are
   // ignored (X could be positive or negative, so the output sign is unknown).
-  if (FMF.noNaNs() && FMF.noSignedZeros() && match(Op0, m_AnyZero()))
-    return Op0;
+  if (FMF.noNaNs() && FMF.noSignedZeros() && match(Op0, m_AnyZeroFP()))
+    return ConstantFP::getNullValue(Op0->getType());
 
   if (FMF.noNaNs()) {
     // X / X -> 1.0 is legal when NaNs are ignored.