diff options
| -rw-r--r-- | docs/LangRef.html | 5 | ||||
| -rw-r--r-- | include/llvm/Attributes.h | 29 | ||||
| -rw-r--r-- | lib/AsmParser/LLParser.cpp | 28 | ||||
| -rw-r--r-- | lib/AsmParser/LLParser.h | 1 | ||||
| -rw-r--r-- | lib/VMCore/Attributes.cpp | 5 | ||||
| -rw-r--r-- | test/Feature/alignment.ll | 4 |
6 files changed, 71 insertions, 1 deletions
diff --git a/docs/LangRef.html b/docs/LangRef.html index fed2f80696..9590609a87 100644 --- a/docs/LangRef.html +++ b/docs/LangRef.html @@ -1078,6 +1078,11 @@ define void @f() optsize { ... } </div> <dl> + <dt><tt><b>alignstack(<<em>n</em>>)</b></tt></dt> + <dd>This attribute indicates that, when emitting the prologue and epilogue, + the backend should forcibly align the stack pointer. Specify the + desired alignment, which must be a power of two, in parentheses. + <dt><tt><b>alwaysinline</b></tt></dt> <dd>This attribute indicates that the inliner should attempt to inline this function into callers whenever possible, ignoring any active inlining size diff --git a/include/llvm/Attributes.h b/include/llvm/Attributes.h index 068f81fc7d..126c290b5a 100644 --- a/include/llvm/Attributes.h +++ b/include/llvm/Attributes.h @@ -60,6 +60,11 @@ const Attributes NoImplicitFloat = 1<<23; /// disable implicit floating point const Attributes Naked = 1<<24; ///< Naked function const Attributes InlineHint = 1<<25; ///< source said inlining was ///desirable +const Attributes StackAlignment = 31<<26; ///< Alignment of stack for + ///function (5 bits) stored as log2 + ///of alignment with +1 bias + ///0 means unaligned (different from + ///alignstack(1)) /// @brief Attributes that only apply to function parameters. const Attributes ParameterOnly = ByVal | Nest | StructRet | NoCapture; @@ -68,7 +73,7 @@ const Attributes ParameterOnly = ByVal | Nest | StructRet | NoCapture; /// be used on return values or function parameters. const Attributes FunctionOnly = NoReturn | NoUnwind | ReadNone | ReadOnly | NoInline | AlwaysInline | OptimizeForSize | StackProtect | StackProtectReq | - NoRedZone | NoImplicitFloat | Naked | InlineHint; + NoRedZone | NoImplicitFloat | Naked | InlineHint | StackAlignment; /// @brief Parameter attributes that do not apply to vararg call arguments. const Attributes VarArgsIncompatible = StructRet; @@ -105,6 +110,28 @@ inline unsigned getAlignmentFromAttrs(Attributes A) { return 1U << ((Align >> 16) - 1); } +/// This turns an int stack alignment (which must be a power of 2) into +/// the form used internally in Attributes. +inline Attributes constructStackAlignmentFromInt(unsigned i) { + // Default alignment, allow the target to define how to align it. + if (i == 0) + return 0; + + assert(isPowerOf2_32(i) && "Alignment must be a power of two."); + assert(i <= 0x40000000 && "Alignment too large."); + return (Log2_32(i)+1) << 26; +} + +/// This returns the stack alignment field of an attribute as a byte alignment +/// value. +inline unsigned getStackAlignmentFromAttrs(Attributes A) { + Attributes StackAlign = A & Attribute::StackAlignment; + if (StackAlign == 0) + return 0; + + return 1U << ((StackAlign >> 26) - 1); +} + /// The set of Attributes set in Attributes is converted to a /// string of equivalent mnemonics. This is, presumably, for writing out diff --git a/lib/AsmParser/LLParser.cpp b/lib/AsmParser/LLParser.cpp index 5dd65691a3..4dab11826b 100644 --- a/lib/AsmParser/LLParser.cpp +++ b/lib/AsmParser/LLParser.cpp @@ -956,6 +956,14 @@ bool LLParser::ParseOptionalAttrs(unsigned &Attrs, unsigned AttrKind) { case lltok::kw_noimplicitfloat: Attrs |= Attribute::NoImplicitFloat; break; case lltok::kw_naked: Attrs |= Attribute::Naked; break; + case lltok::kw_alignstack: { + unsigned Alignment; + if (ParseOptionalStackAlignment(Alignment)) + return true; + Attrs |= Attribute::constructStackAlignmentFromInt(Alignment); + continue; + } + case lltok::kw_align: { unsigned Alignment; if (ParseOptionalAlignment(Alignment)) @@ -963,6 +971,7 @@ bool LLParser::ParseOptionalAttrs(unsigned &Attrs, unsigned AttrKind) { Attrs |= Attribute::constructAlignmentFromInt(Alignment); continue; } + } Lex.Lex(); } @@ -1131,6 +1140,25 @@ bool LLParser::ParseOptionalCommaAlign(unsigned &Alignment, return false; } +/// ParseOptionalStackAlignment +/// ::= /* empty */ +/// ::= 'alignstack' '(' 4 ')' +bool LLParser::ParseOptionalStackAlignment(unsigned &Alignment) { + Alignment = 0; + if (!EatIfPresent(lltok::kw_alignstack)) + return false; + LocTy ParenLoc = Lex.getLoc(); + if (!EatIfPresent(lltok::lparen)) + return Error(ParenLoc, "expected '('"); + LocTy AlignLoc = Lex.getLoc(); + if (ParseUInt32(Alignment)) return true; + ParenLoc = Lex.getLoc(); + if (!EatIfPresent(lltok::rparen)) + return Error(ParenLoc, "expected ')'"); + if (!isPowerOf2_32(Alignment)) + return Error(AlignLoc, "stack alignment is not a power of two"); + return false; +} /// ParseIndexList - This parses the index list for an insert/extractvalue /// instruction. This sets AteExtraComma in the case where we eat an extra diff --git a/lib/AsmParser/LLParser.h b/lib/AsmParser/LLParser.h index 85c07ffa8f..ed7a1d7117 100644 --- a/lib/AsmParser/LLParser.h +++ b/lib/AsmParser/LLParser.h @@ -169,6 +169,7 @@ namespace llvm { bool ParseOptionalVisibility(unsigned &Visibility); bool ParseOptionalCallingConv(CallingConv::ID &CC); bool ParseOptionalAlignment(unsigned &Alignment); + bool ParseOptionalStackAlignment(unsigned &Alignment); bool ParseInstructionMetadata(SmallVectorImpl<std::pair<unsigned, MDNode *> > &); bool ParseOptionalCommaAlign(unsigned &Alignment, bool &AteExtraComma); diff --git a/lib/VMCore/Attributes.cpp b/lib/VMCore/Attributes.cpp index a371c6f92e..6fa597e958 100644 --- a/lib/VMCore/Attributes.cpp +++ b/lib/VMCore/Attributes.cpp @@ -70,6 +70,11 @@ std::string Attribute::getAsString(Attributes Attrs) { Result += "noimplicitfloat "; if (Attrs & Attribute::Naked) Result += "naked "; + if (Attrs & Attribute::StackAlignment) { + Result += "alignstack("; + Result += utostr(Attribute::getStackAlignmentFromAttrs(Attrs)); + Result += ") "; + } if (Attrs & Attribute::Alignment) { Result += "align "; Result += utostr(Attribute::getAlignmentFromAttrs(Attrs)); diff --git a/test/Feature/alignment.ll b/test/Feature/alignment.ll index 409efebe84..ef35a1344a 100644 --- a/test/Feature/alignment.ll +++ b/test/Feature/alignment.ll @@ -19,3 +19,7 @@ define i32* @test2() { ret i32* %X } +define void @test3() alignstack(16) { + ret void +} + |