commit c6944f795d846ae55f8375dd0f8f8ef2045d4cfb
author Sanjay Patel <spatel@rotateright.com> Thu Aug 09 22:20:44 2018 +0000
committer Sanjay Patel <spatel@rotateright.com> Thu Aug 09 22:20:44 2018 +0000
tree 3cf71c4520086ee23bfaa13682383a4742e64ad6
parent 94abc57e3751f591fdb0655419eb129252d1f9c7

[InstSimplify] move minnum/maxnum with Inf folds from instcombine

llvm-svn: 339396

llvm/lib/Analysis/InstructionSimplify.cpp

diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index 1380543..9d317b4 100644
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -4812,7 +4812,7 @@
     }
     break;
   case Intrinsic::maxnum:
-  case Intrinsic::minnum:
+  case Intrinsic::minnum: {
     // If the arguments are the same, this is a no-op.
     if (Op0 == Op1) return Op0;
 
@@ -4831,7 +4831,22 @@
           (M1->getOperand(0) == Op0 || M1->getOperand(1) == Op0))
         return Op1;
 
+    // minnum(X, -Inf) --> -Inf (and commuted variant)
+    // maxnum(X, +Inf) --> +Inf (and commuted variant)
+    bool UseNegInf = IID == Intrinsic::minnum;
+    const APFloat *C;
+    if ((match(Op0, m_APFloat(C)) && C->isInfinity() &&
+         C->isNegative() == UseNegInf) ||
+        (match(Op1, m_APFloat(C)) && C->isInfinity() &&
+         C->isNegative() == UseNegInf))
+      return ConstantFP::getInfinity(ReturnType, UseNegInf);
+
+    // TODO: minnum(nnan x, inf) -> x
+    // TODO: minnum(nnan ninf x, flt_max) -> x
+    // TODO: maxnum(nnan x, -inf) -> x
+    // TODO: maxnum(nnan ninf x, -flt_max) -> x
     break;
+  }
   default:
     break;
   }

llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
index dcd080e..310b87e 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -1133,37 +1133,6 @@
   return nullptr;
 }
 
-static Value *simplifyMinnumMaxnum(const IntrinsicInst &II) {
-  Value *Arg0 = II.getArgOperand(0);
-  Value *Arg1 = II.getArgOperand(1);
-
-  const auto *C1 = dyn_cast<ConstantFP>(Arg1);
-
-  // fmin(x, nan) -> x
-  if (C1 && C1->isNaN())
-    return Arg0;
-
-  if (II.getIntrinsicID() == Intrinsic::minnum) {
-    // TODO: fmin(nnan x, inf) -> x
-    // TODO: fmin(nnan ninf x, flt_max) -> x
-    if (C1 && C1->isInfinity()) {
-      // fmin(x, -inf) -> -inf
-      if (C1->isNegative())
-        return Arg1;
-    }
-  } else {
-    assert(II.getIntrinsicID() == Intrinsic::maxnum);
-    // TODO: fmax(nnan x, -inf) -> x
-    // TODO: fmax(nnan ninf x, -flt_max) -> x
-    if (C1 && C1->isInfinity()) {
-      // fmax(x, inf) -> inf
-      if (!C1->isNegative())
-        return Arg1;
-    }
-  }
-  return nullptr;
-}
-
 static bool maskIsAllOneOrUndef(Value *Mask) {
   auto *ConstMask = dyn_cast<Constant>(Mask);
   if (!ConstMask)
@@ -2000,10 +1969,6 @@
       return II;
     }
 
-    // FIXME: Simplifications should be in instsimplify.
-    if (Value *V = simplifyMinnumMaxnum(*II))
-      return replaceInstUsesWith(*II, V);
-
     Value *X, *Y;
     if (match(Arg0, m_FNeg(m_Value(X))) && match(Arg1, m_FNeg(m_Value(Y))) &&
         (Arg0->hasOneUse() || Arg1->hasOneUse())) {