r237418 - Revert r237385, "[CodeGen] Reuse stack space from unused function results"
NAKAMURA Takumi
geek4civic at gmail.com
Thu May 14 20:49:05 PDT 2015
Author: chapuni
Date: Thu May 14 22:49:05 2015
New Revision: 237418
URL: http://llvm.org/viewvc/llvm-project?rev=237418&view=rev
Log:
Revert r237385, "[CodeGen] Reuse stack space from unused function results"
It broke clang stage2, at least tblgen.
Removed:
cfe/trunk/test/CodeGenCXX/stack-reuse.cpp
Modified:
cfe/trunk/lib/CodeGen/CGCall.cpp
Modified: cfe/trunk/lib/CodeGen/CGCall.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGCall.cpp?rev=237418&r1=237417&r2=237418&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGCall.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGCall.cpp Thu May 14 22:49:05 2015
@@ -3077,18 +3077,10 @@ RValue CodeGenFunction::EmitCall(const C
// If the call returns a temporary with struct return, create a temporary
// alloca to hold the result, unless one is given to us.
llvm::Value *SRetPtr = nullptr;
- size_t UnusedReturnSize = 0;
if (RetAI.isIndirect() || RetAI.isInAlloca()) {
SRetPtr = ReturnValue.getValue();
- if (!SRetPtr) {
+ if (!SRetPtr)
SRetPtr = CreateMemTemp(RetTy);
- if (HaveInsertPoint()) {
- uint64_t size =
- CGM.getDataLayout().getTypeAllocSize(ConvertTypeForMem(RetTy));
- if (EmitLifetimeStart(size, SRetPtr))
- UnusedReturnSize = size;
- }
- }
if (IRFunctionArgs.hasSRetArg()) {
IRCallArgs[IRFunctionArgs.getSRetArgNo()] = SRetPtr;
} else {
@@ -3420,10 +3412,6 @@ RValue CodeGenFunction::EmitCall(const C
// insertion point; this allows the rest of IRgen to discard
// unreachable code.
if (CS.doesNotReturn()) {
- if (UnusedReturnSize)
- EmitLifetimeEnd(llvm::ConstantInt::get(Int64Ty, UnusedReturnSize),
- SRetPtr);
-
Builder.CreateUnreachable();
Builder.ClearInsertionPoint();
@@ -3452,13 +3440,8 @@ RValue CodeGenFunction::EmitCall(const C
RValue Ret = [&] {
switch (RetAI.getKind()) {
case ABIArgInfo::InAlloca:
- case ABIArgInfo::Indirect: {
- RValue ret = convertTempToRValue(SRetPtr, RetTy, SourceLocation());
- if (UnusedReturnSize)
- EmitLifetimeEnd(llvm::ConstantInt::get(Int64Ty, UnusedReturnSize),
- SRetPtr);
- return ret;
- }
+ case ABIArgInfo::Indirect:
+ return convertTempToRValue(SRetPtr, RetTy, SourceLocation());
case ABIArgInfo::Ignore:
// If we are ignoring an argument that had a result, make sure to
Removed: cfe/trunk/test/CodeGenCXX/stack-reuse.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/stack-reuse.cpp?rev=237417&view=auto
==============================================================================
--- cfe/trunk/test/CodeGenCXX/stack-reuse.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/stack-reuse.cpp (removed)
@@ -1,125 +0,0 @@
-// RUN: %clang -target armv7l-unknown-linux-gnueabihf -S %s -o - -emit-llvm -O1 -disable-llvm-optzns | FileCheck %s
-
-// Stack should be reused when possible, no need to allocate two separate slots
-// if they have disjoint lifetime.
-
-// Sizes of objects are related to previously existed threshold of 32. In case
-// of S_large stack size is rounded to 40 bytes.
-
-// 32B
-struct S_small {
- int a[8];
-};
-
-// 36B
-struct S_large {
- int a[9];
-};
-
-extern S_small foo_small();
-extern S_large foo_large();
-extern void bar_small(S_small*);
-extern void bar_large(S_large*);
-
-// Prevent mangling of function names.
-extern "C" {
-
-void small_rvoed_unnamed_temporary_object() {
-// CHECK-LABEL: define void @small_rvoed_unnamed_temporary_object
-// CHECK: call void @llvm.lifetime.start
-// CHECK: call void @_Z9foo_smallv
-// CHECK: call void @llvm.lifetime.end
-// CHECK: call void @llvm.lifetime.start
-// CHECK: call void @_Z9foo_smallv
-// CHECK: call void @llvm.lifetime.end
-
- foo_small();
- foo_small();
-}
-
-void large_rvoed_unnamed_temporary_object() {
-// CHECK-LABEL: define void @large_rvoed_unnamed_temporary_object
-// CHECK: call void @llvm.lifetime.start
-// CHECK: call void @_Z9foo_largev
-// CHECK: call void @llvm.lifetime.end
-// CHECK: call void @llvm.lifetime.start
-// CHECK: call void @_Z9foo_largev
-// CHECK: call void @llvm.lifetime.end
-
- foo_large();
- foo_large();
-}
-
-void small_rvoed_named_temporary_object() {
-// CHECK-LABEL: define void @small_rvoed_named_temporary_object
-// CHECK: call void @llvm.lifetime.start
-// CHECK: call void @_Z9foo_smallv
-// CHECK: call void @llvm.lifetime.end
-// CHECK: call void @llvm.lifetime.start
-// CHECK: call void @_Z9foo_smallv
-// CHECK: call void @llvm.lifetime.end
-
- {
- S_small s = foo_small();
- }
- {
- S_small s = foo_small();
- }
-}
-
-void large_rvoed_named_temporary_object() {
-// CHECK-LABEL: define void @large_rvoed_named_temporary_object
-// CHECK: call void @llvm.lifetime.start
-// CHECK: call void @_Z9foo_largev
-// CHECK: call void @llvm.lifetime.end
-// CHECK: call void @llvm.lifetime.start
-// CHECK: call void @_Z9foo_largev
-// CHECK: call void @llvm.lifetime.end
-
- {
- S_large s = foo_large();
- }
- {
- S_large s = foo_large();
- }
-}
-
-void small_auto_object() {
-// CHECK-LABEL: define void @small_auto_object
-// CHECK: call void @llvm.lifetime.start
-// CHECK: call void @_Z9bar_smallP7S_small
-// CHECK: call void @llvm.lifetime.end
-// CHECK: call void @llvm.lifetime.start
-// CHECK: call void @_Z9bar_smallP7S_small
-// CHECK: call void @llvm.lifetime.end
-
- {
- S_small s;
- bar_small(&s);
- }
- {
- S_small s;
- bar_small(&s);
- }
-}
-
-void large_auto_object() {
-// CHECK-LABEL: define void @large_auto_object
-// CHECK: call void @llvm.lifetime.start
-// CHECK: call void @_Z9bar_largeP7S_large
-// CHECK: call void @llvm.lifetime.end
-// CHECK: call void @llvm.lifetime.start
-// CHECK: call void @_Z9bar_largeP7S_large
-// CHECK: call void @llvm.lifetime.end
-
- {
- S_large s;
- bar_large(&s);
- }
- {
- S_large s;
- bar_large(&s);
- }
-}
-
-}
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