Start trying to make InstCombine preserve more debug info. The idea here is to set the debug location on the IRBuilder, which will be then right location in most cases. This should magically give many transformations debug locations, and fixing places which are missing a debug location will usually just means changing the code creating it to use the IRBuilder.

As an example, the change to InstCombineCalls catches a common case where a call to a bitcast of a function is rewritten.

Chris, does this approach look reasonable?



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131516 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 10 insertions, 9 deletions

diff --git a/lib/Transforms/InstCombine/InstCombineCalls.cpp b/lib/Transforms/InstCombine/InstCombineCalls.cpp
index 08185f5..344fc4f 100644
--- a/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -1106,15 +1106,15 @@ bool InstCombiner::transformConstExprCastCall(CallSite CS) {
 
   Instruction *NC;
   if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) {
-    NC = InvokeInst::Create(Callee, II->getNormalDest(), II->getUnwindDest(),
-                            Args.begin(), Args.end(),
-                            Caller->getName(), Caller);
+    NC = Builder->CreateInvoke(Callee, II->getNormalDest(),
+                               II->getUnwindDest(), Args.begin(), Args.end());
+    NC->takeName(II);
     cast<InvokeInst>(NC)->setCallingConv(II->getCallingConv());
     cast<InvokeInst>(NC)->setAttributes(NewCallerPAL);
   } else {
-    NC = CallInst::Create(Callee, Args.begin(), Args.end(),
-                          Caller->getName(), Caller);
     CallInst *CI = cast<CallInst>(Caller);
+    NC = Builder->CreateCall(Callee, Args.begin(), Args.end());
+    NC->takeName(CI);
     if (CI->isTailCall())
       cast<CallInst>(NC)->setTailCall();
     cast<CallInst>(NC)->setCallingConv(CI->getCallingConv());
diff --git a/lib/Transforms/InstCombine/InstructionCombining.cpp b/lib/Transforms/InstCombine/InstructionCombining.cpp
index 3441cf6..f56cdf6 100644
--- a/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -1575,6 +1575,7 @@ bool InstCombiner::DoOneIteration(Function &F, unsigned Iteration) {
 
     // Now that we have an instruction, try combining it to simplify it.
     Builder->SetInsertPoint(I->getParent(), I);
+    Builder->SetCurrentDebugLocation(I->getDebugLoc());
     
 #ifndef NDEBUG
     std::string OrigI;
diff --git a/test/Transforms/InstCombine/call.ll b/test/Transforms/InstCombine/call.ll
index 2ef8dc0..d084873 100644
--- a/test/Transforms/InstCombine/call.ll
+++ b/test/Transforms/InstCombine/call.ll
@@ -53,8 +53,8 @@ define i8 @test4a() {
 define i32 @test4() {
         %X = call i32 bitcast (i8 ()* @test4a to i32 ()*)( )            ; <i32> [#uses=1]
         ret i32 %X
-; CHECK: %X1 = call i8 @test4a()
-; CHECK: %tmp = zext i8 %X1 to i32
+; CHECK: %X = call i8 @test4a()
+; CHECK: %tmp = zext i8 %X to i32
 ; CHECK: ret i32 %tmp
 }
 
@@ -77,8 +77,8 @@ declare i32 @test6a(i32)
 define i32 @test6() {
         %X = call i32 bitcast (i32 (i32)* @test6a to i32 ()*)( )
         ret i32 %X
-; CHECK: %X1 = call i32 @test6a(i32 0)
-; CHECK: ret i32 %X1
+; CHECK: %X = call i32 @test6a(i32 0)
+; CHECK: ret i32 %X
 }