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Merge pull request #402 from pengtu/master

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Fix a bug where an unsigned index variable in subscript is sxt to 64 bit
This commit is contained in:
Jean-Luc Duprat
2012-11-05 21:51:38 -08:00
parent da4390aede 04d32ae3e6
commit ecc54fa0eb
1 changed files with 30 additions and 9 deletions
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25
expr.cpp
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@@ -4318,15 +4318,36 @@ IndexExpr::TypeCheck() {
bool isUniform = (index->GetType()->IsUniformType() && bool isUniform = (index->GetType()->IsUniformType() &&
!g->opt.disableUniformMemoryOptimizations); !g->opt.disableUniformMemoryOptimizations);
if (!isUniform) {
// Unless we have an explicit 64-bit index and are compiling to a // Unless we have an explicit 64-bit index and are compiling to a
// 64-bit target with 64-bit addressing, convert the index to an int32 // 64-bit target with 64-bit addressing, convert the index to an int32
// type. // type.
// The range of varying index is limited to [0,2^31) as a result.
if (Type::EqualIgnoringConst(indexType->GetAsUniformType(), if (Type::EqualIgnoringConst(indexType->GetAsUniformType(),
AtomicType::UniformInt64) == false || AtomicType::UniformInt64) == false ||
g->target.is32Bit || g->target.is32Bit ||
g->opt.force32BitAddressing) { g->opt.force32BitAddressing) {
const Type *indexType = isUniform ? AtomicType::UniformInt32 : const Type *indexType = AtomicType::VaryingInt32;
AtomicType::VaryingInt32; index = TypeConvertExpr(index, indexType, "array index");
if (index == NULL)
return NULL;
}
} else { // isUniform
// For 32-bit target:
// force the index to 32 bit.
// For 64-bit target:
// We don't want to limit the index range.
// We sxt/zxt the index to 64 bit right here because
// LLVM doesn't distinguish unsigned from signed (both are i32)
//
// However, the index can be still truncated to signed int32 if
// the index type is 64 bit and --addressing=32.
bool force_32bit = g->target.is32Bit ||
(g->opt.force32BitAddressing &&
Type::EqualIgnoringConst(indexType->GetAsUniformType(),
AtomicType::UniformInt64));
const Type *indexType = force_32bit ?
AtomicType::UniformInt32 : AtomicType::UniformInt64;
index = TypeConvertExpr(index, indexType, "array index"); index = TypeConvertExpr(index, indexType, "array index");
if (index == NULL) if (index == NULL)
return NULL; return NULL;