From d35f46caf10bcf366569793bb1d24a6e82e917f7 Mon Sep 17 00:00:00 2001
From: Matt Arsenault <Matthew.Arsenault@amd.com>
Date: Fri, 10 Aug 2018 18:58:49 +0000
Subject: AMDGPU: Turn class x, p_zero|n_zero into fcmp oeq x, 0

The library does use this for some reason.

llvm-svn: 339461
---
 llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp | 9 +++++++++
 1 file changed, 9 insertions(+)

(limited to 'llvm/lib')

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
index 310b87e931c..f0c4cebd7fd 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -3195,6 +3195,15 @@ Instruction *InstCombiner::visitCallInst(CallInst &CI) {
       return replaceInstUsesWith(*II, FCmp);
     }
 
+    if (Mask == (N_ZERO | P_ZERO)) {
+      // Equivalent of == 0.
+      Value *FCmp = Builder.CreateFCmpOEQ(
+        Src0, ConstantFP::get(Src0->getType(), 0.0));
+
+      FCmp->takeName(II);
+      return replaceInstUsesWith(*II, FCmp);
+    }
+
     const ConstantFP *CVal = dyn_cast<ConstantFP>(Src0);
     if (!CVal) {
       if (isa<UndefValue>(Src0))
-- 
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