6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-06-23 01:24:30 +00:00
Code Issues Projects Releases Wiki Activity

[SystemZ] Use CLC and IPM to implement memcmp

Browse Source 
For now this is restricted to fixed-length comparisons with a length
in the range [1, 256], as for memcpy() and MVC.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188163 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Richard Sandiford
2013-08-12 10:28:10 +00:00
parent e03a56d62f
commit ac168b8bc8
12 changed files with 324 additions and 12 deletions
Download Patch File Download Diff File Expand all files Collapse all files

21
lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
View File

@ -58,6 +58,7 @@
#include "llvm/Target/TargetLibraryInfo.h"
#include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Target/TargetSelectionDAGInfo.h"
#include <algorithm>
using namespace llvm;
@ -5463,6 +5464,26 @@ bool SelectionDAGBuilder::visitMemCmpCall(const CallInst &I) {
return false;
const ConstantInt *Size = dyn_cast<ConstantInt>(I.getArgOperand(2));
if (Size && Size->getZExtValue() == 0) {
EVT CallVT = TM.getTargetLowering()->getValueType(I.getType(), true);
setValue(&I, DAG.getConstant(0, CallVT));
return true;
}
const Value *Arg0 = I.getArgOperand(0);
const Value *Arg1 = I.getArgOperand(1);
const Value *Arg2 = I.getArgOperand(2);
const TargetSelectionDAGInfo &TSI = DAG.getSelectionDAGInfo();
std::pair<SDValue, SDValue> Res =
TSI.EmitTargetCodeForMemcmp(DAG, getCurSDLoc(), DAG.getRoot(),
getValue(Arg0), getValue(Arg1), getValue(Arg2),
MachinePointerInfo(Arg0),
MachinePointerInfo(Arg1));
if (Res.first.getNode()) {
setValue(&I, Res.first);
DAG.setRoot(Res.second);
return true;
}
// memcmp(S1,S2,2) != 0 -> (*(short*)LHS != *(short*)RHS) != 0
// memcmp(S1,S2,4) != 0 -> (*(int*)LHS != *(int*)RHS) != 0