maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

IRgen/x86_32/Linux: Linux seems to align all stack objects to 4 bytes, unlike 

Darwin. Checked vs the handiest Linux llvm-gcc I had around, someone on Linux is
welcome to investigate more.

llvm-svn: 114112
This commit is contained in:
Daniel Dunbar 2010-09-16 20:41:56 +00:00
parent c81256a595
commit 8a6c91ff76
2 changed files with 74 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
clang/lib/CodeGen/TargetInfo.cpp
View File

@ -336,6 +336,8 @@ ABIArgInfo DefaultABIInfo::classifyArgumentType(QualType Ty) const {
/// X86_32ABIInfo - The X86-32 ABI information.
class X86_32ABIInfo : public ABIInfo {
static const unsigned MinABIStackAlignInBytes = 4;
bool IsDarwinVectorABI;
bool IsSmallStructInRegABI;
@ -349,6 +351,9 @@ class X86_32ABIInfo : public ABIInfo {
/// such that the argument will be passed in memory.
ABIArgInfo getIndirectResult(QualType Ty, bool ByVal = true) const;
/// \brief Return the alignment to use for the given type on the stack.
unsigned getTypeStackAlignInBytes(QualType Ty) const;
public:
ABIArgInfo classifyReturnType(QualType RetTy) const;
@ -547,15 +552,30 @@ ABIArgInfo X86_32ABIInfo::classifyReturnType(QualType RetTy) const {
ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
}
unsigned X86_32ABIInfo::getTypeStackAlignInBytes(QualType Ty) const {
// On non-Darwin, the stack type alignment is always 4.
if (!IsDarwinVectorABI)
return MinABIStackAlignInBytes;
// Otherwise, if the alignment is less than or equal to 4, use the minimum ABI
// alignment.
unsigned Align = getContext().getTypeAlign(Ty) / 8;
if (Align <= MinABIStackAlignInBytes)
return MinABIStackAlignInBytes;
// Otherwise, if the type contains SSE or MMX vector types, then the alignment
// matches that of the struct.
return Align;
}
ABIArgInfo X86_32ABIInfo::getIndirectResult(QualType Ty, bool ByVal) const {
if (!ByVal)
return ABIArgInfo::getIndirect(0, false);
// Compute the byval alignment. We trust the back-end to honor the
// minimum ABI alignment for byval, to make cleaner IR.
const unsigned MinABIAlign = 4;
unsigned Align = getContext().getTypeAlign(Ty) / 8;
if (Align > MinABIAlign)
unsigned Align = getTypeStackAlignInBytes(Ty);
if (Align > MinABIStackAlignInBytes)
return ABIArgInfo::getIndirect(Align);
return ABIArgInfo::getIndirect(0);
}

51
clang/test/CodeGen/x86_32-arguments-linux.c Normal file
View File

@ -0,0 +1,51 @@
// RUN: %clang_cc1 -w -fblocks -triple i386-pc-linux-gnu -emit-llvm -o %t %s
// RUN: FileCheck < %t %s
// CHECK: define void @f56(
// CHECK: i8 signext %a0, %struct.s56_0* byval %a1,
// CHECK: <2 x i32> %a2, %struct.s56_1* byval %a3,
// CHECK: <1 x double> %a4, %struct.s56_2* byval %a5,
// CHECK: <4 x i32> %a6, %struct.s56_3* byval %a7,
// CHECK: <2 x double> %a8, %struct.s56_4* byval %a9,
// CHECK: <8 x i32> %a10, %struct.s56_5* byval %a11,
// CHECK: <4 x double> %a12, %struct.s56_6* byval %a13)
// CHECK: call void (i32, ...)* @f56_0(i32 1,
// CHECK: i32 %{{.*}}, %struct.s56_0* byval %{{[^ ]*}},
// CHECK: <2 x i32> %{{[^ ]*}}, %struct.s56_1* byval %{{[^ ]*}},
// CHECK: <1 x double> %{{[^ ]*}}, %struct.s56_2* byval %{{[^ ]*}},
// CHECK: <4 x i32> %{{[^ ]*}}, %struct.s56_3* byval %{{[^ ]*}},
// CHECK: <2 x double> %{{[^ ]*}}, %struct.s56_4* byval %{{[^ ]*}},
// CHECK: <8 x i32> %{{[^ ]*}}, %struct.s56_5* byval %{{[^ ]*}},
// CHECK: <4 x double> %{{[^ ]*}}, %struct.s56_6* byval %{{[^ ]*}})
// CHECK: }
//
// <rdar://problem/7964854> [i386] clang misaligns long double in structures
// when passed byval
// <rdar://problem/8431367> clang misaligns parameters on stack
typedef int __attribute__((vector_size (8))) t56_v2i;
typedef double __attribute__((vector_size (8))) t56_v1d;
typedef int __attribute__((vector_size (16))) t56_v4i;
typedef double __attribute__((vector_size (16))) t56_v2d;
typedef int __attribute__((vector_size (32))) t56_v8i;
typedef double __attribute__((vector_size (32))) t56_v4d;
struct s56_0 { char a; };
struct s56_1 { t56_v2i a; };
struct s56_2 { t56_v1d a; };
struct s56_3 { t56_v4i a; };
struct s56_4 { t56_v2d a; };
struct s56_5 { t56_v8i a; };
struct s56_6 { t56_v4d a; };
void f56(char a0, struct s56_0 a1,
t56_v2i a2, struct s56_1 a3,
t56_v1d a4, struct s56_2 a5,
t56_v4i a6, struct s56_3 a7,
t56_v2d a8, struct s56_4 a9,
t56_v8i a10, struct s56_5 a11,
t56_v4d a12, struct s56_6 a13) {
extern void f56_0(int x, ...);
f56_0(1, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9,
a10, a11, a12, a13);
}