From cc2caa3c8bcb80e840d0b5756cabd8e7d6f18d63 Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper@intel.com>
Date: Fri, 8 Mar 2019 23:03:43 +0000
Subject: [PATCH] [ScalarizeMaskedMemIntrin] Only set the ModifiedDT flag if
 new basic blocks were added.

There are special cases in the scalarization for constant masks. If we hit one of the special cases we don't need to reset the iteration.

Noticed while starting work on adding expandload/compressstore to this pass.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@355754 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/ScalarizeMaskedMemIntrin.cpp | 28 ++++++++++++++----------
 1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/lib/CodeGen/ScalarizeMaskedMemIntrin.cpp b/lib/CodeGen/ScalarizeMaskedMemIntrin.cpp
index 103ba7661d9..18a4c84e0e3 100644
--- a/lib/CodeGen/ScalarizeMaskedMemIntrin.cpp
+++ b/lib/CodeGen/ScalarizeMaskedMemIntrin.cpp
@@ -123,7 +123,7 @@ static bool isConstantIntVector(Value *Mask) {
 //  %10 = extractelement <16 x i1> %mask, i32 2
 //  br i1 %10, label %cond.load4, label %else5
 //
-static void scalarizeMaskedLoad(CallInst *CI) {
+static void scalarizeMaskedLoad(CallInst *CI, bool &ModifiedDT) {
   Value *Ptr = CI->getArgOperand(0);
   Value *Alignment = CI->getArgOperand(1);
   Value *Mask = CI->getArgOperand(2);
@@ -221,6 +221,8 @@ static void scalarizeMaskedLoad(CallInst *CI) {
 
   CI->replaceAllUsesWith(VResult);
   CI->eraseFromParent();
+
+  ModifiedDT = true;
 }
 
 // Translate a masked store intrinsic, like
@@ -249,7 +251,7 @@ static void scalarizeMaskedLoad(CallInst *CI) {
 //   store i32 %6, i32* %7
 //   br label %else2
 //   . . .
-static void scalarizeMaskedStore(CallInst *CI) {
+static void scalarizeMaskedStore(CallInst *CI, bool &ModifiedDT) {
   Value *Src = CI->getArgOperand(0);
   Value *Ptr = CI->getArgOperand(1);
   Value *Alignment = CI->getArgOperand(2);
@@ -328,6 +330,8 @@ static void scalarizeMaskedStore(CallInst *CI) {
     IfBlock = NewIfBlock;
   }
   CI->eraseFromParent();
+
+  ModifiedDT = true;
 }
 
 // Translate a masked gather intrinsic like
@@ -359,7 +363,7 @@ static void scalarizeMaskedStore(CallInst *CI) {
 // . . .
 // %Result = select <16 x i1> %Mask, <16 x i32> %res.phi.select, <16 x i32> %Src
 // ret <16 x i32> %Result
-static void scalarizeMaskedGather(CallInst *CI) {
+static void scalarizeMaskedGather(CallInst *CI, bool &ModifiedDT) {
   Value *Ptrs = CI->getArgOperand(0);
   Value *Alignment = CI->getArgOperand(1);
   Value *Mask = CI->getArgOperand(2);
@@ -441,6 +445,8 @@ static void scalarizeMaskedGather(CallInst *CI) {
 
   CI->replaceAllUsesWith(VResult);
   CI->eraseFromParent();
+
+  ModifiedDT = true;
 }
 
 // Translate a masked scatter intrinsic, like
@@ -469,7 +475,7 @@ static void scalarizeMaskedGather(CallInst *CI) {
 // store i32 %Elt1, i32* %Ptr1, align 4
 // br label %else2
 //   . . .
-static void scalarizeMaskedScatter(CallInst *CI) {
+static void scalarizeMaskedScatter(CallInst *CI, bool &ModifiedDT) {
   Value *Src = CI->getArgOperand(0);
   Value *Ptrs = CI->getArgOperand(1);
   Value *Alignment = CI->getArgOperand(2);
@@ -538,6 +544,8 @@ static void scalarizeMaskedScatter(CallInst *CI) {
     IfBlock = NewIfBlock;
   }
   CI->eraseFromParent();
+
+  ModifiedDT = true;
 }
 
 bool ScalarizeMaskedMemIntrin::runOnFunction(Function &F) {
@@ -588,29 +596,25 @@ bool ScalarizeMaskedMemIntrin::optimizeCallInst(CallInst *CI,
     case Intrinsic::masked_load:
       // Scalarize unsupported vector masked load
       if (!TTI->isLegalMaskedLoad(CI->getType())) {
-        scalarizeMaskedLoad(CI);
-        ModifiedDT = true;
+        scalarizeMaskedLoad(CI, ModifiedDT);
         return true;
       }
       return false;
     case Intrinsic::masked_store:
       if (!TTI->isLegalMaskedStore(CI->getArgOperand(0)->getType())) {
-        scalarizeMaskedStore(CI);
-        ModifiedDT = true;
+        scalarizeMaskedStore(CI, ModifiedDT);
         return true;
       }
       return false;
     case Intrinsic::masked_gather:
       if (!TTI->isLegalMaskedGather(CI->getType())) {
-        scalarizeMaskedGather(CI);
-        ModifiedDT = true;
+        scalarizeMaskedGather(CI, ModifiedDT);
         return true;
       }
       return false;
     case Intrinsic::masked_scatter:
       if (!TTI->isLegalMaskedScatter(CI->getArgOperand(0)->getType())) {
-        scalarizeMaskedScatter(CI);
-        ModifiedDT = true;
+        scalarizeMaskedScatter(CI, ModifiedDT);
         return true;
       }
       return false;
-- 
2.50.1