6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-02-06 23:32:27 +00:00
Code Issues Projects Releases Wiki Activity

Don't insert lifetime.end markers between a musttail call and ret

Browse Source 
The allocas going out of scope are immediately killed by the return
instruction.

Reviewers: chandlerc

Differential Revision: http://reviews.llvm.org/D3630

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208912 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Reid Kleckner 2014-05-15 20:39:13 +00:00
parent 44623e8781
commit 24a50c5797
2 changed files with 48 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
lib/Transforms/Utils/InlineFunction.cpp
View File

@ -758,10 +758,15 @@ bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI,
} }
builder.CreateLifetimeStart(AI, AllocaSize); builder.CreateLifetimeStart(AI, AllocaSize);
for (ReturnInst *RI : Returns) for (ReturnInst *RI : Returns) {
// Don't insert llvm.lifetime.end calls between a musttail call and a
// return. The return kills all local allocas.
if (InlinedMustTailCalls && getPrecedingMustTailCall(RI))
continue;
IRBuilder<>(RI).CreateLifetimeEnd(AI, AllocaSize); IRBuilder<>(RI).CreateLifetimeEnd(AI, AllocaSize);
} }
} }
}
// If the inlined code contained dynamic alloca instructions, wrap the inlined // If the inlined code contained dynamic alloca instructions, wrap the inlined
// code with llvm.stacksave/llvm.stackrestore intrinsics. // code with llvm.stacksave/llvm.stackrestore intrinsics.
@ -777,9 +782,14 @@ bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI,
// Insert a call to llvm.stackrestore before any return instructions in the // Insert a call to llvm.stackrestore before any return instructions in the
// inlined function. // inlined function.
for (ReturnInst *RI : Returns) for (ReturnInst *RI : Returns) {
// Don't insert llvm.stackrestore calls between a musttail call and a
// return. The return will restore the stack pointer.
if (InlinedMustTailCalls && getPrecedingMustTailCall(RI))
continue;
IRBuilder<>(RI).CreateCall(StackRestore, SavedPtr); IRBuilder<>(RI).CreateCall(StackRestore, SavedPtr);
} }
}
// If we are inlining for an invoke instruction, we must make sure to rewrite // If we are inlining for an invoke instruction, we must make sure to rewrite
// any call instructions into invoke instructions. // any call instructions into invoke instructions.

36
test/Transforms/Inline/inline-tail.ll
View File

@ -49,6 +49,42 @@ define void @test_musttail_basic_a(i32* %p) {
ret void ret void
} }
; Don't insert lifetime end markers here, the lifetime is trivially over due
; the return.
; CHECK: define void @test_byval_a(
; CHECK: musttail call void @test_byval_c(
; CHECK-NEXT: ret void
declare void @test_byval_c(i32* byval %p)
define internal void @test_byval_b(i32* byval %p) {
musttail call void @test_byval_c(i32* byval %p)
ret void
}
define void @test_byval_a(i32* byval %p) {
musttail call void @test_byval_b(i32* byval %p)
ret void
}
; Don't insert a stack restore, we're about to return.
; CHECK: define void @test_dynalloca_a(
; CHECK: call i8* @llvm.stacksave(
; CHECK: alloca i8, i32 %n
; CHECK: musttail call void @test_dynalloca_c(
; CHECK-NEXT: ret void
declare void @escape(i8* %buf)
declare void @test_dynalloca_c(i32* byval %p, i32 %n)
define internal void @test_dynalloca_b(i32* byval %p, i32 %n) alwaysinline {
%buf = alloca i8, i32 %n ; dynamic alloca
call void @escape(i8* %buf) ; escape it
musttail call void @test_dynalloca_c(i32* byval %p, i32 %n)
ret void
}
define void @test_dynalloca_a(i32* byval %p, i32 %n) {
musttail call void @test_dynalloca_b(i32* byval %p, i32 %n)
ret void
}
; We can't merge the returns. ; We can't merge the returns.
; CHECK: define void @test_multiret_a( ; CHECK: define void @test_multiret_a(
; CHECK: musttail call void @test_multiret_c( ; CHECK: musttail call void @test_multiret_c(