From: Craig Topper <craig.topper@gmail.com>
Date: Fri, 26 May 2017 22:42:34 +0000 (+0000)
Subject: [InstSimplify] Push commuted op checks for and/or of icmp further down to avoid dupli... 
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=996f62f0e824431f3af5cb7b34c6333bdd9d30ad;p=llvm

[InstSimplify] Push commuted op checks for and/or of icmp further down to avoid duplicate work

Previously, we called simplifyPossiblyCastedAndOrOfICmps twice with the operands commuted, but the call to simplifyAndOrOfICmpsWithConstants further down already handles commuting and doesn't need to be called both ways.

This patch pushes double calls further down to just the individual routines that need to be called twice.

Differential Revision: https://reviews.llvm.org/D33603

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304044 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp
index 6033d3fe500..122442bafb1 100644
--- a/lib/Analysis/InstructionSimplify.cpp
+++ b/lib/Analysis/InstructionSimplify.cpp
@@ -1422,6 +1422,8 @@ Value *llvm::SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact,
   return ::SimplifyAShrInst(Op0, Op1, isExact, Q, RecursionLimit);
 }
 
+/// Commuted variants are assumed to be handled by calling this function again
+/// with the parameters swapped.
 static Value *simplifyUnsignedRangeCheck(ICmpInst *ZeroICmp,
                                          ICmpInst *UnsignedICmp, bool IsAnd) {
   Value *X, *Y;
@@ -1554,18 +1556,7 @@ static Value *simplifyAndOrOfICmpsWithConstants(ICmpInst *Cmp0, ICmpInst *Cmp1,
   return nullptr;
 }
 
-/// Commuted variants are assumed to be handled by calling this function again
-/// with the parameters swapped.
-static Value *simplifyAndOfICmps(ICmpInst *Op0, ICmpInst *Op1) {
-  if (Value *X = simplifyUnsignedRangeCheck(Op0, Op1, /*IsAnd=*/true))
-    return X;
-
-  if (Value *X = simplifyAndOfICmpsWithSameOperands(Op0, Op1))
-    return X;
-
-  if (Value *X = simplifyAndOrOfICmpsWithConstants(Op0, Op1, true))
-    return X;
-
+static Value *simplifyAndOfICmpsWithAdd(ICmpInst *Op0, ICmpInst *Op1) {
   // (icmp (add V, C0), C1) & (icmp V, C0)
   ICmpInst::Predicate Pred0, Pred1;
   const APInt *C0, *C1;
@@ -1611,18 +1602,29 @@ static Value *simplifyAndOfICmps(ICmpInst *Op0, ICmpInst *Op1) {
   return nullptr;
 }
 
-/// Commuted variants are assumed to be handled by calling this function again
-/// with the parameters swapped.
-static Value *simplifyOrOfICmps(ICmpInst *Op0, ICmpInst *Op1) {
-  if (Value *X = simplifyUnsignedRangeCheck(Op0, Op1, /*IsAnd=*/false))
+static Value *simplifyAndOfICmps(ICmpInst *Op0, ICmpInst *Op1) {
+  if (Value *X = simplifyUnsignedRangeCheck(Op0, Op1, /*IsAnd=*/true))
+    return X;
+  if (Value *X = simplifyUnsignedRangeCheck(Op1, Op0, /*IsAnd=*/true))
     return X;
 
-  if (Value *X = simplifyOrOfICmpsWithSameOperands(Op0, Op1))
+  if (Value *X = simplifyAndOfICmpsWithSameOperands(Op0, Op1))
+    return X;
+  if (Value *X = simplifyAndOfICmpsWithSameOperands(Op1, Op0))
     return X;
 
-  if (Value *X = simplifyAndOrOfICmpsWithConstants(Op0, Op1, false))
+  if (Value *X = simplifyAndOrOfICmpsWithConstants(Op0, Op1, true))
+    return X;
+
+  if (Value *X = simplifyAndOfICmpsWithAdd(Op0, Op1))
     return X;
+  if (Value *X = simplifyAndOfICmpsWithAdd(Op1, Op0))
+    return X;
+
+  return nullptr;
+}
 
+static Value *simplifyOrOfICmpsWithAdd(ICmpInst *Op0, ICmpInst *Op1) {
   // (icmp (add V, C0), C1) | (icmp V, C0)
   ICmpInst::Predicate Pred0, Pred1;
   const APInt *C0, *C1;
@@ -1668,19 +1670,24 @@ static Value *simplifyOrOfICmps(ICmpInst *Op0, ICmpInst *Op1) {
   return nullptr;
 }
 
-static Value *simplifyPossiblyCastedAndOrOfICmps(ICmpInst *Cmp0, ICmpInst *Cmp1,
-                                                 bool IsAnd, CastInst *Cast) {
-  Value *V =
-      IsAnd ? simplifyAndOfICmps(Cmp0, Cmp1) : simplifyOrOfICmps(Cmp0, Cmp1);
-  if (!V)
-    return nullptr;
-  if (!Cast)
-    return V;
+static Value *simplifyOrOfICmps(ICmpInst *Op0, ICmpInst *Op1) {
+  if (Value *X = simplifyUnsignedRangeCheck(Op0, Op1, /*IsAnd=*/false))
+    return X;
+  if (Value *X = simplifyUnsignedRangeCheck(Op1, Op0, /*IsAnd=*/false))
+    return X;
 
-  // If we looked through casts, we can only handle a constant simplification
-  // because we are not allowed to create a cast instruction here.
-  if (auto *C = dyn_cast<Constant>(V))
-    return ConstantExpr::getCast(Cast->getOpcode(), C, Cast->getType());
+  if (Value *X = simplifyOrOfICmpsWithSameOperands(Op0, Op1))
+    return X;
+  if (Value *X = simplifyOrOfICmpsWithSameOperands(Op1, Op0))
+    return X;
+
+  if (Value *X = simplifyAndOrOfICmpsWithConstants(Op0, Op1, false))
+    return X;
+
+  if (Value *X = simplifyOrOfICmpsWithAdd(Op0, Op1))
+    return X;
+  if (Value *X = simplifyOrOfICmpsWithAdd(Op1, Op0))
+    return X;
 
   return nullptr;
 }
@@ -1700,11 +1707,18 @@ static Value *simplifyAndOrOfICmps(Value *Op0, Value *Op1, bool IsAnd) {
   if (!Cmp0 || !Cmp1)
     return nullptr;
 
-  if (Value *V = simplifyPossiblyCastedAndOrOfICmps(Cmp0, Cmp1, IsAnd, Cast0))
-    return V;
-  if (Value *V = simplifyPossiblyCastedAndOrOfICmps(Cmp1, Cmp0, IsAnd, Cast0))
+  Value *V =
+      IsAnd ? simplifyAndOfICmps(Cmp0, Cmp1) : simplifyOrOfICmps(Cmp0, Cmp1);
+  if (!V)
+    return nullptr;
+  if (!Cast0)
     return V;
 
+  // If we looked through casts, we can only handle a constant simplification
+  // because we are not allowed to create a cast instruction here.
+  if (auto *C = dyn_cast<Constant>(V))
+    return ConstantExpr::getCast(Cast0->getOpcode(), C, Cast0->getType());
+
   return nullptr;
 }