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| author | Chris Lattner <sabre@nondot.org> | 2012-02-20 00:42:49 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2012-02-20 00:42:49 +0000 |
| commit | b053fc1c92b6b81c47d5e2c092b0f3ea04fd5b87 (patch) | |
| tree | 185c5b92d6e2538f8c30edc1202c4d253529713f /lib/Transforms/InstCombine/InstCombineAddSub.cpp | |
| parent | 637f949a7fc97aa42e7360e9ed9462316b772d88 (diff) | |
fold comparisons of gep'd alloca points with null to false,
implementing PR12013. We now compile the testcase to:
__Z4testv: ## @_Z4testv
## BB#0: ## %_ZN4llvm15SmallVectorImplIiE9push_backERKi.exit
pushq %rbx
subq $64, %rsp
leaq 32(%rsp), %rbx
movq %rbx, (%rsp)
leaq 64(%rsp), %rax
movq %rax, 16(%rsp)
movl $1, 32(%rsp)
leaq 36(%rsp), %rax
movq %rax, 8(%rsp)
leaq (%rsp), %rdi
callq __Z1gRN4llvm11SmallVectorIiLj8EEE
movq (%rsp), %rdi
cmpq %rbx, %rdi
je LBB0_2
## BB#1:
callq _free
LBB0_2: ## %_ZN4llvm11SmallVectorIiLj8EED1Ev.exit
addq $64, %rsp
popq %rbx
ret
instead of:
__Z4testv: ## @_Z4testv
## BB#0:
pushq %rbx
subq $64, %rsp
xorl %eax, %eax
leaq (%rsp), %rbx
addq $32, %rbx
movq %rbx, (%rsp)
movq %rbx, 8(%rsp)
leaq 64(%rsp), %rcx
movq %rcx, 16(%rsp)
je LBB0_2
## BB#1:
movl $1, 32(%rsp)
movq %rbx, %rax
LBB0_2: ## %_ZN4llvm15SmallVectorImplIiE9push_backERKi.exit
addq $4, %rax
movq %rax, 8(%rsp)
leaq (%rsp), %rdi
callq __Z1gRN4llvm11SmallVectorIiLj8EEE
movq (%rsp), %rdi
cmpq %rbx, %rdi
je LBB0_4
## BB#3:
callq _free
LBB0_4: ## %_ZN4llvm11SmallVectorIiLj8EED1Ev.exit
addq $64, %rsp
popq %rbx
ret
This doesn't shrink clang noticably though.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150944 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms/InstCombine/InstCombineAddSub.cpp')
0 files changed, 0 insertions, 0 deletions