Code that checks WillNotOverflowSignedAdd before creating an Add

can safely use the NSW bit on the Add.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85164 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index a1d3c9736ef0db41fccdeb6010089e1b7b90e814..7c0d22359fdd4c18711ad96cf6240c7d3858ddd9 100644 (file)
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -2420,8 +2420,8 @@ Instruction *InstCombiner::visitAdd(BinaryOperator &I) {
           ConstantExpr::getSExt(CI, I.getType()) == RHSC &&
           WillNotOverflowSignedAdd(LHSConv->getOperand(0), CI)) {
         // Insert the new, smaller add.
-        Value *NewAdd = Builder->CreateAdd(LHSConv->getOperand(0), 
-                                           CI, "addconv");
+        Value *NewAdd = Builder->CreateNSWAdd(LHSConv->getOperand(0), 
+                                              CI, "addconv");
         return new SExtInst(NewAdd, I.getType());
       }
     }
@@ -2436,8 +2436,8 @@ Instruction *InstCombiner::visitAdd(BinaryOperator &I) {
           WillNotOverflowSignedAdd(LHSConv->getOperand(0),
                                    RHSConv->getOperand(0))) {
         // Insert the new integer add.
-        Value *NewAdd = Builder->CreateAdd(LHSConv->getOperand(0), 
-                                           RHSConv->getOperand(0), "addconv");
+        Value *NewAdd = Builder->CreateNSWAdd(LHSConv->getOperand(0), 
+                                              RHSConv->getOperand(0), "addconv");
         return new SExtInst(NewAdd, I.getType());
       }
     }
@@ -2493,8 +2493,8 @@ Instruction *InstCombiner::visitFAdd(BinaryOperator &I) {
           ConstantExpr::getSIToFP(CI, I.getType()) == CFP &&
           WillNotOverflowSignedAdd(LHSConv->getOperand(0), CI)) {
         // Insert the new integer add.
-        Value *NewAdd = Builder->CreateAdd(LHSConv->getOperand(0),
-                                           CI, "addconv");
+        Value *NewAdd = Builder->CreateNSWAdd(LHSConv->getOperand(0),
+                                              CI, "addconv");
         return new SIToFPInst(NewAdd, I.getType());
       }
     }
@@ -2509,8 +2509,8 @@ Instruction *InstCombiner::visitFAdd(BinaryOperator &I) {
           WillNotOverflowSignedAdd(LHSConv->getOperand(0),
                                    RHSConv->getOperand(0))) {
         // Insert the new integer add.
-        Value *NewAdd = Builder->CreateAdd(LHSConv->getOperand(0), 
-                                           RHSConv->getOperand(0), "addconv");
+        Value *NewAdd = Builder->CreateNSWAdd(LHSConv->getOperand(0), 
+                                              RHSConv->getOperand(0), "addconv");
         return new SIToFPInst(NewAdd, I.getType());
       }
     }

diff --git a/test/Transforms/InstCombine/add-shrink.ll b/test/Transforms/InstCombine/add-shrink.ll
index 52b8e327dbaeecf0c7147848eab60a9da78ec02e..cc5747866311a42daf08e6175c37169c2a4e65f5 100644 (file)
--- a/test/Transforms/InstCombine/add-shrink.ll
+++ b/test/Transforms/InstCombine/add-shrink.ll
@@ -1,4 +1,4 @@
-; RUN: opt < %s -instcombine -S | grep {add i32}
+; RUN: opt < %s -instcombine -S | grep {add nsw i32}
 ; RUN: opt < %s -instcombine -S | grep sext | count 1
 
 ; Should only have one sext and the add should be i32 instead of i64.

diff --git a/test/Transforms/InstCombine/add-sitofp.ll b/test/Transforms/InstCombine/add-sitofp.ll
index 24319df0b76208bcd29581b8632769e48814ec9a..98a8cb452a6ceece91b6f0c9a10d6f8aeaf11359 100644 (file)
--- a/test/Transforms/InstCombine/add-sitofp.ll
+++ b/test/Transforms/InstCombine/add-sitofp.ll
@@ -1,4 +1,4 @@
-; RUN: opt < %s -instcombine -S | grep {add i32}
+; RUN: opt < %s -instcombine -S | grep {add nsw i32}
 
 define double @x(i32 %a, i32 %b) nounwind {
   %m = lshr i32 %a, 24