[InstSimplify] move minnum/maxnum with same arg fold from instcombine

llvm-svn: 338652
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index 7fc7c15..b1601bf 100644
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -4764,6 +4764,9 @@
     break;
   case Intrinsic::maxnum:
   case Intrinsic::minnum:
+    // If the arguments are the same, this is a no-op.
+    if (Op0 == Op1) return Op0;
+
     // If one argument is NaN, return the other argument.
     if (match(Op0, m_NaN())) return Op1;
     if (match(Op1, m_NaN())) return Op0;
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
index cbfbd8a..77c5a06 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -1137,10 +1137,6 @@
   Value *Arg0 = II.getArgOperand(0);
   Value *Arg1 = II.getArgOperand(1);
 
-  // fmin(x, x) -> x
-  if (Arg0 == Arg1)
-    return Arg0;
-
   const auto *C1 = dyn_cast<ConstantFP>(Arg1);
 
   // fmin(x, nan) -> x
diff --git a/llvm/test/Transforms/InstCombine/maxnum.ll b/llvm/test/Transforms/InstCombine/maxnum.ll
index 11bff42..ff415aa 100644
--- a/llvm/test/Transforms/InstCombine/maxnum.ll
+++ b/llvm/test/Transforms/InstCombine/maxnum.ll
@@ -129,14 +129,6 @@
   ret float %y
 }
 
-define float @noop_maxnum_f32(float %x) {
-; CHECK-LABEL: @noop_maxnum_f32(
-; CHECK-NEXT:    ret float [[X:%.*]]
-;
-  %y = call float @llvm.maxnum.f32(float %x, float %x)
-  ret float %y
-}
-
 define float @maxnum_f32_nan_val(float %x) {
 ; CHECK-LABEL: @maxnum_f32_nan_val(
 ; CHECK-NEXT:    ret float [[X:%.*]]
diff --git a/llvm/test/Transforms/InstCombine/minnum.ll b/llvm/test/Transforms/InstCombine/minnum.ll
index a05ce8c..7cf9d1b 100644
--- a/llvm/test/Transforms/InstCombine/minnum.ll
+++ b/llvm/test/Transforms/InstCombine/minnum.ll
@@ -131,14 +131,6 @@
   ret float %y
 }
 
-define float @noop_minnum_f32(float %x) {
-; CHECK-LABEL: @noop_minnum_f32(
-; CHECK-NEXT:    ret float [[X:%.*]]
-;
-  %y = call float @llvm.minnum.f32(float %x, float %x)
-  ret float %y
-}
-
 define float @minnum_f32_nan_val(float %x) {
 ; CHECK-LABEL: @minnum_f32_nan_val(
 ; CHECK-NEXT:    ret float [[X:%.*]]
diff --git a/llvm/test/Transforms/InstSimplify/floating-point-arithmetic.ll b/llvm/test/Transforms/InstSimplify/floating-point-arithmetic.ll
index afd375f..ca9226d 100644
--- a/llvm/test/Transforms/InstSimplify/floating-point-arithmetic.ll
+++ b/llvm/test/Transforms/InstSimplify/floating-point-arithmetic.ll
@@ -463,14 +463,15 @@
   ret float %fabs
 }
 
+declare float @llvm.minnum.f32(float, float)
+declare float @llvm.maxnum.f32(float, float)
 declare double @llvm.minnum.f64(double, double)
 declare double @llvm.maxnum.f64(double, double)
 declare <2 x double> @llvm.minnum.v2f64(<2 x double>, <2 x double>)
 declare <2 x double> @llvm.maxnum.v2f64(<2 x double>, <2 x double>)
 
 ; From the LangRef for minnum/maxnum:
-; "follows the IEEE-754 semantics for maxNum, which also match for libm’s fmax.
-; If either operand is a NaN, returns the other non-NaN operand."
+; "If either operand is a NaN, returns the other non-NaN operand."
 
 define double @maxnum_nan_op0(double %x) {
 ; CHECK-LABEL: @maxnum_nan_op0(
@@ -536,3 +537,19 @@
   ret <2 x double> %r
 }
 
+define float @minnum_same_args(float %x) {
+; CHECK-LABEL: @minnum_same_args(
+; CHECK-NEXT:    ret float [[X:%.*]]
+;
+  %y = call float @llvm.minnum.f32(float %x, float %x)
+  ret float %y
+}
+
+define float @maxnum_same_args(float %x) {
+; CHECK-LABEL: @maxnum_same_args(
+; CHECK-NEXT:    ret float [[X:%.*]]
+;
+  %y = call float @llvm.maxnum.f32(float %x, float %x)
+  ret float %y
+}
+