[ValueTracking] Allow select patterns to work on FP vectors

Summary:
This CL allows constant vectors of floats to be recognized as non-NaN
and non-zero in select patterns. This change makes
`matchSelectPattern` more powerful generally, but was motivated
specifically because I wanted fminnan and fmaxnan to be created for
vector versions of the scalar patterns they are created for.

Tested with check-all on all targets. A testcase in the WebAssembly
backend that tests the non-nan codepath is in an upcoming CL.

Reviewers: aheejin, dschuff

Subscribers: sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D52324

llvm-svn: 343364

1 files changed, 22 insertions, 0 deletions

diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 495324f..02d0717 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -4397,12 +4397,34 @@ static bool isKnownNonNaN(const Value *V, FastMathFlags FMF) {
 
   if (auto *C = dyn_cast<ConstantFP>(V))
     return !C->isNaN();
+
+  if (auto *C = dyn_cast<ConstantDataVector>(V)) {
+    if (!C->getElementType()->isFloatingPointTy())
+      return false;
+    for (unsigned I = 0, E = C->getNumElements(); I < E; ++I) {
+      if (C->getElementAsAPFloat(I).isNaN())
+        return false;
+    }
+    return true;
+  }
+
   return false;
 }
 
 static bool isKnownNonZero(const Value *V) {
   if (auto *C = dyn_cast<ConstantFP>(V))
     return !C->isZero();
+
+  if (auto *C = dyn_cast<ConstantDataVector>(V)) {
+    if (!C->getElementType()->isFloatingPointTy())
+      return false;
+    for (unsigned I = 0, E = C->getNumElements(); I < E; ++I) {
+      if (C->getElementAsAPFloat(I).isZero())
+        return false;
+    }
+    return true;
+  }
+
   return false;
 }