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[MC] Don't crash on modulo by zero (PR35650) 

Extension to D12776, handle modulo by zero in the same way we handle divide by zero.

Differential Revision: https://reviews.llvm.org/D43631

llvm-svn: 325810
This commit is contained in:
Simon Pilgrim 2018-02-22 18:06:48 +00:00
parent 925529b821
commit 8831f6e57d
2 changed files with 8 additions and 2 deletions
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7
llvm/lib/MC/MCExpr.cpp
View File

@ -754,6 +754,7 @@ bool MCExpr::evaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm,
case MCBinaryExpr::Add: Result = LHS + RHS; break;
case MCBinaryExpr::And: Result = LHS & RHS; break;
case MCBinaryExpr::Div:
case MCBinaryExpr::Mod:
// Handle division by zero. gas just emits a warning and keeps going,
// we try to be stricter.
// FIXME: Currently the caller of this function has no way to understand
@ -762,7 +763,10 @@ bool MCExpr::evaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm,
// change this code to emit a better diagnostic.
if (RHS == 0)
return false;
Result = LHS / RHS;
if (ABE->getOpcode() == MCBinaryExpr::Div)
Result = LHS / RHS;
else
Result = LHS % RHS;
break;
case MCBinaryExpr::EQ: Result = LHS == RHS; break;
case MCBinaryExpr::GT: Result = LHS > RHS; break;
@ -772,7 +776,6 @@ bool MCExpr::evaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm,
case MCBinaryExpr::LShr: Result = uint64_t(LHS) >> uint64_t(RHS); break;
case MCBinaryExpr::LT: Result = LHS < RHS; break;
case MCBinaryExpr::LTE: Result = LHS <= RHS; break;
case MCBinaryExpr::Mod: Result = LHS % RHS; break;
case MCBinaryExpr::Mul: Result = LHS * RHS; break;
case MCBinaryExpr::NE: Result = LHS != RHS; break;
case MCBinaryExpr::Or: Result = LHS | RHS; break;

3
llvm/test/MC/ELF/div-by-zero.s
View File

@ -4,3 +4,6 @@
// CHECK: expected relocatable expression
.int 1/0
// CHECK: expected relocatable expression
.int 2%0