diff options
| author | Chris Lattner <sabre@nondot.org> | 2010-09-05 02:18:34 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2010-09-05 02:18:34 +0000 |
| commit | beac75da3784929aee9f0357fc5cd76d49d6c3d7 (patch) | |
| tree | 54525601bcdb388c49b9d014c90e6cbe8dbc1467 /lib/Target/X86/X86InstrInfo.h | |
| parent | 07c2b7ff685523458f92339facfd814689e55873 (diff) | |
| download | external_llvm-beac75da3784929aee9f0357fc5cd76d49d6c3d7.zip external_llvm-beac75da3784929aee9f0357fc5cd76d49d6c3d7.tar.gz external_llvm-beac75da3784929aee9f0357fc5cd76d49d6c3d7.tar.bz2 | |
implement rdar://6653118 - fastisel should fold loads where possible.
Since mem2reg isn't run at -O0, we get a ton of reloads from the stack,
for example, before, this code:
int foo(int x, int y, int z) {
return x+y+z;
}
used to compile into:
_foo: ## @foo
subq $12, %rsp
movl %edi, 8(%rsp)
movl %esi, 4(%rsp)
movl %edx, (%rsp)
movl 8(%rsp), %edx
movl 4(%rsp), %esi
addl %edx, %esi
movl (%rsp), %edx
addl %esi, %edx
movl %edx, %eax
addq $12, %rsp
ret
Now we produce:
_foo: ## @foo
subq $12, %rsp
movl %edi, 8(%rsp)
movl %esi, 4(%rsp)
movl %edx, (%rsp)
movl 8(%rsp), %edx
addl 4(%rsp), %edx ## Folded load
addl (%rsp), %edx ## Folded load
movl %edx, %eax
addq $12, %rsp
ret
Fewer instructions and less register use = faster compiles.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113102 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/X86/X86InstrInfo.h')
| -rw-r--r-- | lib/Target/X86/X86InstrInfo.h | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/lib/Target/X86/X86InstrInfo.h b/lib/Target/X86/X86InstrInfo.h index f336206..eb0e4b8 100644 --- a/lib/Target/X86/X86InstrInfo.h +++ b/lib/Target/X86/X86InstrInfo.h @@ -845,18 +845,18 @@ public: /// SetSSEDomain - Set the SSEDomain of MI. void SetSSEDomain(MachineInstr *MI, unsigned Domain) const; + MachineInstr* foldMemoryOperandImpl(MachineFunction &MF, + MachineInstr* MI, + unsigned OpNum, + const SmallVectorImpl<MachineOperand> &MOs, + unsigned Size, unsigned Alignment) const; + private: MachineInstr * convertToThreeAddressWithLEA(unsigned MIOpc, MachineFunction::iterator &MFI, MachineBasicBlock::iterator &MBBI, LiveVariables *LV) const; - MachineInstr* foldMemoryOperandImpl(MachineFunction &MF, - MachineInstr* MI, - unsigned OpNum, - const SmallVectorImpl<MachineOperand> &MOs, - unsigned Size, unsigned Alignment) const; - /// isFrameOperand - Return true and the FrameIndex if the specified /// operand and follow operands form a reference to the stack frame. bool isFrameOperand(const MachineInstr *MI, unsigned int Op, |