Giorgis Georgakoudis c6275bc0ce [CodeExtractor] Replace uses of extracted bitcasts in out-of-region lifetime markers ... CodeExtractor handles bitcasts in the extracted region that have lifetime markers users in the outer region as outputs. That creates unnecessary alloca/reload instructions and extra lifetime markers. The patch identifies those cases, and replaces uses in out-of-region lifetime markers with new bitcasts in the outer region. **Example** ``` define void @foo() { entry: %0 = alloca i32 br label %extract extract: %1 = bitcast i32* %0 to i8* call void @llvm.lifetime.start.p0i8(i64 4, i8* %1) call void @use(i32* %0) br label %exit exit: call void @use(i32* %0) call void @llvm.lifetime.end.p0i8(i64 4, i8* %1) ret void } ``` **Current extraction** ``` define void @foo() { entry: %.loc = alloca i8*, align 8 %0 = alloca i32, align 4 br label %codeRepl codeRepl: ; preds = %entry %lt.cast = bitcast i8** %.loc to i8* call void @llvm.lifetime.start.p0i8(i64 -1, i8* %lt.cast) %lt.cast1 = bitcast i32* %0 to i8* call void @llvm.lifetime.start.p0i8(i64 -1, i8* %lt.cast1) call void @foo.extract(i32* %0, i8** %.loc) %.reload = load i8*, i8** %.loc, align 8 call void @llvm.lifetime.end.p0i8(i64 -1, i8* %lt.cast) br label %exit exit: ; preds = %codeRepl call void @use(i32* %0) call void @llvm.lifetime.end.p0i8(i64 4, i8* %.reload) ret void } define internal void @foo.extract(i32* %0, i8** %.out) { newFuncRoot: br label %extract exit.exitStub: ; preds = %extract ret void extract: ; preds = %newFuncRoot %1 = bitcast i32* %0 to i8* store i8* %1, i8** %.out, align 8 call void @use(i32* %0) br label %exit.exitStub } ``` **Extraction with patch** ``` define void @foo() { entry: %0 = alloca i32, align 4 br label %codeRepl codeRepl: ; preds = %entry %lt.cast1 = bitcast i32* %0 to i8* call void @llvm.lifetime.start.p0i8(i64 -1, i8* %lt.cast1) call void @foo.extract(i32* %0) br label %exit exit: ; preds = %codeRepl call void @use(i32* %0) %lt.cast = bitcast i32* %0 to i8* call void @llvm.lifetime.end.p0i8(i64 4, i8* %lt.cast) ret void } define internal void @foo.extract(i32* %0) { newFuncRoot: br label %extract exit.exitStub: ; preds = %extract ret void extract: ; preds = %newFuncRoot %1 = bitcast i32* %0 to i8* call void @use(i32* %0) br label %exit.exitStub } ``` Reviewed By: vsk Differential Revision: https://reviews.llvm.org/D90689		2020-11-05 17:01:08 -08:00
..
ASanStackFrameLayoutTest.cpp
BasicBlockUtilsTest.cpp
CallPromotionUtilsTest.cpp
CloningTest.cpp
CMakeLists.txt
CodeExtractorTest.cpp	[CodeExtractor] Replace uses of extracted bitcasts in out-of-region lifetime markers	2020-11-05 17:01:08 -08:00
CodeMoverUtilsTest.cpp
FunctionComparatorTest.cpp
IntegerDivisionTest.cpp
LocalTest.cpp
LoopRotationUtilsTest.cpp
LoopUtilsTest.cpp
ScalarEvolutionExpanderTest.cpp
SizeOptsTest.cpp
SSAUpdaterBulkTest.cpp
UnrollLoopTest.cpp
ValueMapperTest.cpp
VFABIUtils.cpp