ValueTracking: Address todo for nan fmul handling in computeKnownFPClass

If both operands can't be zero or nan, the result can't be nan.

1 files changed, 25 insertions, 1 deletions

diff --git a/llvm/unittests/Analysis/ValueTrackingTest.cpp b/llvm/unittests/Analysis/ValueTrackingTest.cpp
index ba983d4..211959f 100644
--- a/llvm/unittests/Analysis/ValueTrackingTest.cpp
+++ b/llvm/unittests/Analysis/ValueTrackingTest.cpp
@@ -72,6 +72,8 @@ protected:
     A3 = findInstructionByNameOrNull(F, "A3");
     A4 = findInstructionByNameOrNull(F, "A4");
     A5 = findInstructionByNameOrNull(F, "A5");
+    A6 = findInstructionByNameOrNull(F, "A6");
+    A7 = findInstructionByNameOrNull(F, "A7");
 
     CxtI = findInstructionByNameOrNull(F, "CxtI");
     CxtI2 = findInstructionByNameOrNull(F, "CxtI2");
@@ -83,7 +85,8 @@ protected:
   Function *F = nullptr;
   Instruction *A = nullptr;
   // Instructions (optional)
-  Instruction *A2 = nullptr, *A3 = nullptr, *A4 = nullptr, *A5 = nullptr;
+  Instruction *A2 = nullptr, *A3 = nullptr, *A4 = nullptr, *A5 = nullptr,
+              *A6 = nullptr, *A7 = nullptr;
 
   // Context instructions (optional)
   Instruction *CxtI = nullptr, *CxtI2 = nullptr, *CxtI3 = nullptr;
@@ -1592,6 +1595,27 @@ TEST_F(ComputeKnownFPClassTest, FMul) {
   expectKnownFPClass(fcAllFlags, std::nullopt, A5);
 }
 
+TEST_F(ComputeKnownFPClassTest, FMulNoZero) {
+  parseAssembly(
+      "define float @test(float nofpclass(zero) %no.zero, float nofpclass(zero nan) %no.zero.nan, float nofpclass(nzero nan) %no.negzero.nan, float nofpclass(pzero nan) %no.poszero.nan, float nofpclass(inf nan) %no.inf.nan, float nofpclass(inf) %no.inf, float nofpclass(nan) %no.nan) {\n"
+      "  %A = fmul float %no.zero.nan, %no.zero.nan"
+      "  %A2 = fmul float %no.zero, %no.zero"
+      "  %A3 = fmul float %no.poszero.nan, %no.zero.nan"
+      "  %A4 = fmul float %no.nan, %no.zero"
+      "  %A5 = fmul float %no.zero, %no.inf"
+      "  %A6 = fmul float %no.zero.nan, %no.nan"
+      "  %A7 = fmul float %no.nan, %no.zero.nan"
+      "  ret float %A\n"
+      "}\n");
+  expectKnownFPClass(fcFinite | fcInf, std::nullopt, A);
+  expectKnownFPClass(fcAllFlags, std::nullopt, A2);
+  expectKnownFPClass(fcAllFlags, std::nullopt, A3);
+  expectKnownFPClass(fcAllFlags, std::nullopt, A4);
+  expectKnownFPClass(fcAllFlags, std::nullopt, A5);
+  expectKnownFPClass(fcAllFlags, std::nullopt, A6);
+  expectKnownFPClass(fcAllFlags, std::nullopt, A7);
+}
+
 TEST_F(ValueTrackingTest, isNonZeroRecurrence) {
   parseAssembly(R"(
     define i1 @test(i8 %n, i8 %r) {