RPCSX/llvm
1
0
Fork 0
mirror of https://github.com/RPCSX/llvm.git synced 2024-11-30 23:20:54 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Fix fast-isel address mode folding to avoid folding instructions

Browse Source 
outside of the current basic block. This fixes PR9500, rdar://9156159.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128041 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dan Gohman 2011-03-22 00:04:35 +00:00
parent ce3a1bac4b
commit b55d6b6a7e
2 changed files with 41 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
lib/Target/X86/X86FastISel.cpp
View File

@ -399,33 +399,39 @@ bool X86FastISel::X86SelectAddress(const Value *V, X86AddressMode &AM) {
Disp += SL->getElementOffset(Idx);
} else {
uint64_t S = TD.getTypeAllocSize(GTI.getIndexedType());
SmallVector<const Value *, 4> Worklist;
Worklist.push_back(Op);
do {
Op = Worklist.pop_back_val();
for (;;) {
if (const ConstantInt *CI = dyn_cast<ConstantInt>(Op)) {
// Constant-offset addressing.
Disp += CI->getSExtValue() * S;
} else if (isa<AddOperator>(Op) &&
isa<ConstantInt>(cast<AddOperator>(Op)->getOperand(1))) {
// An add with a constant operand. Fold the constant.
break;
}
if (isa<AddOperator>(Op) &&
(!isa<Instruction>(Op) ||
FuncInfo.MBBMap[cast<Instruction>(Op)->getParent()]
== FuncInfo.MBB) &&
isa<ConstantInt>(cast<AddOperator>(Op)->getOperand(1))) {
// An add (in the same block) with a constant operand. Fold the
// constant.
ConstantInt *CI =
cast<ConstantInt>(cast<AddOperator>(Op)->getOperand(1));
Disp += CI->getSExtValue() * S;
// Add the other operand back to the work list.
Worklist.push_back(cast<AddOperator>(Op)->getOperand(0));
} else if (IndexReg == 0 &&
(!AM.GV || !Subtarget->isPICStyleRIPRel()) &&
(S == 1 || S == 2 || S == 4 || S == 8)) {
// Iterate on the other operand.
Op = cast<AddOperator>(Op)->getOperand(0);
continue;
}
if (IndexReg == 0 &&
(!AM.GV || !Subtarget->isPICStyleRIPRel()) &&
(S == 1 || S == 2 || S == 4 || S == 8)) {
// Scaled-index addressing.
Scale = S;
IndexReg = getRegForGEPIndex(Op).first;
if (IndexReg == 0)
return false;
} else
// Unsupported.
goto unsupported_gep;
} while (!Worklist.empty());
break;
}
// Unsupported.
goto unsupported_gep;
}
}
}
// Check for displacement overflow.

19
test/CodeGen/X86/fast-isel-gep.ll
View File

@ -87,4 +87,23 @@ define i64 @test5(i8* %A, i32 %I, i64 %B) nounwind {
; X64-NEXT: ret
}
; PR9500, rdar://9156159 - Don't do non-local address mode folding,
; because it may require values which wouldn't otherwise be live out
; of their blocks.
define void @test6() {
if.end: ; preds = %if.then, %invoke.cont
%tmp15 = load i64* undef
%dec = add i64 %tmp15, 13
store i64 %dec, i64* undef
%call17 = invoke i8* @_ZNK18G__FastAllocString4dataEv()
to label %invoke.cont16 unwind label %lpad
invoke.cont16: ; preds = %if.then14
%arrayidx18 = getelementptr inbounds i8* %call17, i64 %dec
store i8 0, i8* %arrayidx18
unreachable
lpad: ; preds = %if.end19, %if.then14, %if.end, %entry
unreachable
}
declare i8* @_ZNK18G__FastAllocString4dataEv() nounwind