From 9b6b8228148c88d41c098005133eeea1e1005162 Mon Sep 17 00:00:00 2001 From: David Majnemer Date: Tue, 6 Jan 2015 08:41:31 +0000 Subject: [PATCH] InstCombine: Bitcast call arguments from/to pointer/integer type Try harder to get rid of bitcast'd calls by ptrtoint/inttoptr'ing arguments and return values when DataLayout says it is safe to do so. llvm-svn: 225254 --- .../Transforms/InstCombine/InstCombineCalls.cpp | 17 +++++++--- .../InstCombine/apint-call-cast-target.ll | 9 +++-- .../Transforms/InstCombine/call-cast-target.ll | 38 +++++++++++++++++++++- 3 files changed, 56 insertions(+), 8 deletions(-) diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp index b36edde..11a28d4a 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp @@ -1416,7 +1416,7 @@ bool InstCombiner::transformConstExprCastCall(CallSite CS) { if (NewRetTy->isStructTy()) return false; // TODO: Handle multiple return values. - if (!CastInst::isBitCastable(NewRetTy, OldRetTy)) { + if (!CastInst::isBitOrNoopPointerCastable(NewRetTy, OldRetTy, DL)) { if (Callee->isDeclaration()) return false; // Cannot transform this return value. @@ -1451,12 +1451,21 @@ bool InstCombiner::transformConstExprCastCall(CallSite CS) { unsigned NumActualArgs = CS.arg_size(); unsigned NumCommonArgs = std::min(FT->getNumParams(), NumActualArgs); + // Prevent us turning: + // declare void @takes_i32_inalloca(i32* inalloca) + // call void bitcast (void (i32*)* @takes_i32_inalloca to void (i32)*)(i32 0) + // + // into: + // call void @takes_i32_inalloca(i32* null) + if (Callee->getAttributes().hasAttrSomewhere(Attribute::InAlloca)) + return false; + CallSite::arg_iterator AI = CS.arg_begin(); for (unsigned i = 0, e = NumCommonArgs; i != e; ++i, ++AI) { Type *ParamTy = FT->getParamType(i); Type *ActTy = (*AI)->getType(); - if (!CastInst::isBitCastable(ActTy, ParamTy)) + if (!CastInst::isBitOrNoopPointerCastable(ActTy, ParamTy, DL)) return false; // Cannot transform this parameter value. if (AttrBuilder(CallerPAL.getParamAttributes(i + 1), i + 1). @@ -1551,7 +1560,7 @@ bool InstCombiner::transformConstExprCastCall(CallSite CS) { if ((*AI)->getType() == ParamTy) { Args.push_back(*AI); } else { - Args.push_back(Builder->CreateBitCast(*AI, ParamTy)); + Args.push_back(Builder->CreateBitOrPointerCast(*AI, ParamTy)); } // Add any parameter attributes. @@ -1622,7 +1631,7 @@ bool InstCombiner::transformConstExprCastCall(CallSite CS) { Value *NV = NC; if (OldRetTy != NV->getType() && !Caller->use_empty()) { if (!NV->getType()->isVoidTy()) { - NV = NC = CastInst::Create(CastInst::BitCast, NC, OldRetTy); + NV = NC = CastInst::CreateBitOrPointerCast(NC, OldRetTy); NC->setDebugLoc(Caller->getDebugLoc()); // If this is an invoke instruction, we should insert it after the first diff --git a/llvm/test/Transforms/InstCombine/apint-call-cast-target.ll b/llvm/test/Transforms/InstCombine/apint-call-cast-target.ll index 4e98f9b..f3a66c3 100644 --- a/llvm/test/Transforms/InstCombine/apint-call-cast-target.ll +++ b/llvm/test/Transforms/InstCombine/apint-call-cast-target.ll @@ -5,15 +5,18 @@ target triple = "i686-pc-linux-gnu" define i32 @main() { ; CHECK-LABEL: @main( -; CHECK: call i32 bitcast +; CHECK: %[[call:.*]] = call i7* @ctime(i999* null) +; CHECK: %[[cast:.*]] = ptrtoint i7* %[[call]] to i32 +; CHECK: ret i32 %[[cast]] entry: %tmp = call i32 bitcast (i7* (i999*)* @ctime to i32 (i99*)*)( i99* null ) ret i32 %tmp } define i7* @ctime(i999*) { -; CHECK-LABEL: @ctime( -; CHECK: call i7* bitcast +; CHECK-LABEL: define i7* @ctime( +; CHECK: %[[call:.*]] = call i32 @main() +; CHECK: %[[cast:.*]] = inttoptr i32 %[[call]] to i7* entry: %tmp = call i7* bitcast (i32 ()* @main to i7* ()*)( ) ret i7* %tmp diff --git a/llvm/test/Transforms/InstCombine/call-cast-target.ll b/llvm/test/Transforms/InstCombine/call-cast-target.ll index 1af3317..b82dd99 100644 --- a/llvm/test/Transforms/InstCombine/call-cast-target.ll +++ b/llvm/test/Transforms/InstCombine/call-cast-target.ll @@ -5,7 +5,9 @@ target triple = "i686-pc-linux-gnu" define i32 @main() { ; CHECK-LABEL: @main -; CHECK: call i32 bitcast +; CHECK: %[[call:.*]] = call i8* @ctime(i32* null) +; CHECK: %[[cast:.*]] = ptrtoint i8* %[[call]] to i32 +; CHECK: ret i32 %[[cast]] entry: %tmp = call i32 bitcast (i8* (i32*)* @ctime to i32 (i32*)*)( i32* null ) ; [#uses=1] ret i32 %tmp @@ -25,3 +27,37 @@ entry: %0 = call { i8 } bitcast ({ i8 } (i32*)* @foo to { i8 } (i16*)*)(i16* null) ret void } + +declare i32 @fn1(i32) + +define i32 @test1(i32* %a) { +; CHECK-LABEL: @test1 +; CHECK: %[[cast:.*]] = ptrtoint i32* %a to i32 +; CHECK-NEXT: %[[call:.*]] = tail call i32 @fn1(i32 %[[cast]]) +; CHECK-NEXT: ret i32 %[[call]] +entry: + %call = tail call i32 bitcast (i32 (i32)* @fn1 to i32 (i32*)*)(i32* %a) + ret i32 %call +} + +declare i32 @fn2(i16) + +define i32 @test2(i32* %a) { +; CHECK-LABEL: @test2 +; CHECK: %[[call:.*]] = tail call i32 bitcast (i32 (i16)* @fn2 to i32 (i32*)*)(i32* %a) +; CHECK-NEXT: ret i32 %[[call]] +entry: + %call = tail call i32 bitcast (i32 (i16)* @fn2 to i32 (i32*)*)(i32* %a) + ret i32 %call +} + +declare i32 @fn3(i64) + +define i32 @test3(i32* %a) { +; CHECK-LABEL: @test3 +; CHECK: %[[call:.*]] = tail call i32 bitcast (i32 (i64)* @fn3 to i32 (i32*)*)(i32* %a) +; CHECK-NEXT: ret i32 %[[call]] +entry: + %call = tail call i32 bitcast (i32 (i64)* @fn3 to i32 (i32*)*)(i32* %a) + ret i32 %call +} -- 2.7.4