It turns out that "align 1" and unaligned are different. Add a bias to the

alignment attribute such that 0 means unaligned.

This will probably require a rebuild of llvm-gcc because of the change to
Attributes.h. If you see many test failures on "make check", please rebuild
your llvm-gcc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61030 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Nick Lewycky 2008-12-15 07:29:55 +00:00
parent d17c030276
commit 382da62ec2
4 changed files with 14 additions and 5 deletions

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@ -51,7 +51,8 @@ const Attributes OptimizeForSize = 1<<13; ///< opt_size
const Attributes StackProtect = 1<<14; ///< Stack protection.
const Attributes StackProtectReq = 1<<15; ///< Stack protection required.
const Attributes Alignment = 31<<16; ///< Alignment of parameter (5 bits)
// stored as log2 of alignment.
// stored as log2 of alignment with +1 bias
// 0 means unaligned different from align 1
const Attributes NoCapture = 1<<21; ///< Function creates no aliases of pointer
/// @brief Attributes that only apply to function parameters.
@ -79,7 +80,8 @@ Attributes typeIncompatible(const Type *Ty);
/// form used internally in Attributes.
inline Attributes constructAlignmentFromInt(unsigned i) {
assert(isPowerOf2_32(i) && "Alignment must be a power of two.");
return Log2_32(i) << 16;
assert(i <= 0x40000000 && "Alignment too large.");
return (Log2_32(i)+1) << 16;
}
/// The set of Attributes set in Attributes is converted to a
@ -178,7 +180,7 @@ public:
/// getParamAlignment - Return the alignment for the specified function
/// parameter.
unsigned getParamAlignment(unsigned Idx) const {
return (getAttributes(Idx) & Attribute::Alignment) >> 16;
return 1ull << (((getAttributes(Idx) & Attribute::Alignment) >> 16) - 1);
}
/// hasAttrSomewhere - Return true if the specified attribute is set for at

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@ -1332,6 +1332,8 @@ OptAlign : /*empty*/ { $$ = 0; } |
$$ = $2;
if ($$ != 0 && !isPowerOf2_32($$))
GEN_ERROR("Alignment must be a power of two");
if ($$ > 0x40000000)
GEN_ERROR("Alignment too large");
CHECK_FOR_ERROR
};
OptCAlign : /*empty*/ { $$ = 0; } |
@ -1339,6 +1341,8 @@ OptCAlign : /*empty*/ { $$ = 0; } |
$$ = $3;
if ($$ != 0 && !isPowerOf2_32($$))
GEN_ERROR("Alignment must be a power of two");
if ($$ > 0x40000000)
GEN_ERROR("Alignment too large");
CHECK_FOR_ERROR
};
@ -1368,6 +1372,8 @@ GlobalVarAttribute : SectionString {
| ALIGN EUINT64VAL {
if ($2 != 0 && !isPowerOf2_32($2))
GEN_ERROR("Alignment must be a power of two");
if ($2 > 0x40000000)
GEN_ERROR("Alignment too large");
CurGV->setAlignment($2);
CHECK_FOR_ERROR
};

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@ -128,7 +128,8 @@ static void WriteAttributeTable(const ValueEnumerator &VE,
// 5-bit log2 encoded value. Shift the bits above the alignment up by
// 11 bits.
uint64_t FauxAttr = PAWI.Attrs & 0xffff;
FauxAttr |= (1ull<<16)<<((PAWI.Attrs & Attribute::Alignment) >> 16);
if (PAWI.Attrs & Attribute::Alignment)
FauxAttr |= (1ull<<16)<<(((PAWI.Attrs & Attribute::Alignment)-1) >> 16);
FauxAttr |= (PAWI.Attrs & (0x3FFull << 21)) << 11;
Record.push_back(FauxAttr);

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@ -61,7 +61,7 @@ std::string Attribute::getAsString(Attributes Attrs) {
Result += "sspreq ";
if (Attrs & Attribute::Alignment) {
Result += "align ";
Result += utostr(1ull << ((Attrs & Attribute::Alignment)>>16));
Result += utostr(1ull << (((Attrs & Attribute::Alignment)>>16) - 1));
Result += " ";
}
// Trim the trailing space.