[PATCH] D52324: [ValueTracking] Allow select patterns to work on vectors in more places

[Thomas Lively via Phabricator via llvm-commits]

tlively updated this revision to Diff 167037.
tlively marked 3 inline comments as done.
tlively added a comment.

- Address comments on tests


Repository:
  rL LLVM

https://reviews.llvm.org/D52324

Files:
  lib/Analysis/ValueTracking.cpp
  unittests/Analysis/ValueTrackingTest.cpp


Index: unittests/Analysis/ValueTrackingTest.cpp
===================================================================
--- unittests/Analysis/ValueTrackingTest.cpp
+++ unittests/Analysis/ValueTrackingTest.cpp
@@ -149,6 +149,49 @@
   expectPattern({SPF_FMINNUM, SPNB_RETURNS_OTHER, true});
 }
 
+TEST_F(MatchSelectPatternTest, VectorFMin) {
+  parseAssembly(
+      "define <4 x float> @test(<4 x float> %a) {\n"
+      "  %1 = fcmp ule <4 x float> %a, \n"
+      "    <float 5.0, float 5.0, float 5.0, float 5.0>\n"
+      "  %A = select <4 x i1> %1, <4 x float> %a,\n"
+      "     <4 x float> <float 5.0, float 5.0, float 5.0, float 5.0>\n"
+      "  ret <4 x float> %A\n"
+      "}\n");
+  // Check that pattern matching works on vectors where each lane has the same
+  // pattern.
+  expectPattern({SPF_FMINNUM, SPNB_RETURNS_NAN, false});
+}
+
+TEST_F(MatchSelectPatternTest, VectorNotFMinNaN) {
+  parseAssembly(
+      "define <4 x float> @test(<4 x float> %a) {\n"
+      "  %1 = fcmp ule <4 x float> %a, \n"
+      "    <float 5.0, float 0x7ff8000000000000, float 5.0, float 5.0>\n"
+      "  %A = select <4 x i1> %1, <4 x float> %a,\n"
+      "     <4 x float> <float 5.0, float 0x7ff8000000000000, float 5.0, float "
+      "5.0>\n"
+      "  ret <4 x float> %A\n"
+      "}\n");
+  // The lane that contains a NaN (0x7ff80...) behaves like fminnum and the
+  // other lines behave like fminnan, so check that neither is returned.
+  expectPattern({SPF_UNKNOWN, SPNB_NA, false});
+}
+
+TEST_F(MatchSelectPatternTest, VectorNotFMinZero) {
+  parseAssembly(
+      "define <4 x float> @test(<4 x float> %a) {\n"
+      "  %1 = fcmp ule <4 x float> %a, \n"
+      "    <float 5.0, float -0.0, float 5.0, float 5.0>\n"
+      "  %A = select <4 x i1> %1, <4 x float> %a,\n"
+      "     <4 x float> <float 5.0, float -0.0, float 5.0, float 5.0>\n"
+      "  ret <4 x float> %A\n"
+      "}\n");
+  // Always selects the second lane of %a if it is positive or negative zero, so
+  // this is stricter than a min.
+  expectPattern({SPF_UNKNOWN, SPNB_NA, false});
+}
+
 TEST_F(MatchSelectPatternTest, DoubleCastU) {
   parseAssembly(
       "define i32 @test(i8 %a, i8 %b) {\n"
Index: lib/Analysis/ValueTracking.cpp
===================================================================
--- lib/Analysis/ValueTracking.cpp
+++ lib/Analysis/ValueTracking.cpp
@@ -4397,12 +4397,34 @@
 
   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;
 }
 


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