[InstSimplify] move minnum/maxnum with common op fold from instcombine

llvm-svn: 339144

2 files changed, 11 insertions, 30 deletions

diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index 494ca656dba..02137a51844 100644
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -4805,6 +4805,17 @@ static Value *simplifyBinaryIntrinsic(Function *F, Value *Op0, Value *Op1,
     if (match(Op0, m_CombineOr(m_NaN(), m_Undef()))) return Op1;
     if (match(Op1, m_CombineOr(m_NaN(), m_Undef()))) return Op0;
 
+    // Min/max of the same operation with common operand:
+    // m(m(X, Y)), X --> m(X, Y) (4 commuted variants)
+    if (auto *M0 = dyn_cast<IntrinsicInst>(Op0))
+      if (M0->getIntrinsicID() == IID &&
+          (M0->getOperand(0) == Op1 || M0->getOperand(1) == Op1))
+        return Op0;
+    if (auto *M1 = dyn_cast<IntrinsicInst>(Op1))
+      if (M1->getIntrinsicID() == IID &&
+          (M1->getOperand(0) == Op0 || M1->getOperand(1) == Op0))
+        return Op1;
+
     break;
   default:
     break;
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
index 748cb97d9b5..dcd080e3305 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -1143,23 +1143,7 @@ static Value *simplifyMinnumMaxnum(const IntrinsicInst &II) {
   if (C1 && C1->isNaN())
     return Arg0;
 
-  Value *X = nullptr;
-  Value *Y = nullptr;
   if (II.getIntrinsicID() == Intrinsic::minnum) {
-    // fmin(x, fmin(x, y)) -> fmin(x, y)
-    // fmin(y, fmin(x, y)) -> fmin(x, y)
-    if (match(Arg1, m_FMin(m_Value(X), m_Value(Y)))) {
-      if (Arg0 == X || Arg0 == Y)
-        return Arg1;
-    }
-
-    // fmin(fmin(x, y), x) -> fmin(x, y)
-    // fmin(fmin(x, y), y) -> fmin(x, y)
-    if (match(Arg0, m_FMin(m_Value(X), m_Value(Y)))) {
-      if (Arg1 == X || Arg1 == Y)
-        return Arg0;
-    }
-
     // TODO: fmin(nnan x, inf) -> x
     // TODO: fmin(nnan ninf x, flt_max) -> x
     if (C1 && C1->isInfinity()) {
@@ -1169,20 +1153,6 @@ static Value *simplifyMinnumMaxnum(const IntrinsicInst &II) {
     }
   } else {
     assert(II.getIntrinsicID() == Intrinsic::maxnum);
-    // fmax(x, fmax(x, y)) -> fmax(x, y)
-    // fmax(y, fmax(x, y)) -> fmax(x, y)
-    if (match(Arg1, m_FMax(m_Value(X), m_Value(Y)))) {
-      if (Arg0 == X || Arg0 == Y)
-        return Arg1;
-    }
-
-    // fmax(fmax(x, y), x) -> fmax(x, y)
-    // fmax(fmax(x, y), y) -> fmax(x, y)
-    if (match(Arg0, m_FMax(m_Value(X), m_Value(Y)))) {
-      if (Arg1 == X || Arg1 == Y)
-        return Arg0;
-    }
-
     // TODO: fmax(nnan x, -inf) -> x
     // TODO: fmax(nnan ninf x, -flt_max) -> x
     if (C1 && C1->isInfinity()) {