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[X86] Mark inregs correctly for MCU psABI 

The MCU psABI calling convention is somewhat, but not quite, like -mregparm 3.
In particular, the rules involving structs are different.

Differential Revision: http://reviews.llvm.org/D13978

llvm-svn: 251224
This commit is contained in:
Michael Kuperstein 2015-10-25 08:18:20 +00:00
parent eaa16005af
commit 6890188ea3
2 changed files with 76 additions and 5 deletions
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23
clang/lib/CodeGen/TargetInfo.cpp
View File

@ -799,6 +799,7 @@ class X86_32ABIInfo : public ABIInfo {
bool IsRetSmallStructInRegABI;
bool IsWin32StructABI;
bool IsSoftFloatABI;
bool IsMCUABI;
unsigned DefaultNumRegisterParameters;
static bool isRegisterSize(unsigned Size) {
@ -853,6 +854,7 @@ public:
IsRetSmallStructInRegABI(RetSmallStructInRegABI),
IsWin32StructABI(Win32StructABI),
IsSoftFloatABI(SoftFloatABI),
IsMCUABI(CGT.getTarget().getTriple().isEnvironmentIAMCU()),
DefaultNumRegisterParameters(NumRegisterParameters) {}
};
@ -986,7 +988,7 @@ void X86_32TargetCodeGenInfo::addReturnRegisterOutputs(
}
/// shouldReturnTypeInRegister - Determine if the given type should be
/// returned in a register (for the Darwin ABI).
/// returned in a register (for the Darwin and MCU ABI).
bool X86_32ABIInfo::shouldReturnTypeInRegister(QualType Ty,
ASTContext &Context) const {
uint64_t Size = Context.getTypeSize(Ty);
@ -1226,9 +1228,18 @@ bool X86_32ABIInfo::shouldUseInReg(QualType Ty, CCState &State,
if (SizeInRegs == 0)
return false;
if (SizeInRegs > State.FreeRegs) {
State.FreeRegs = 0;
return false;
if (!IsMCUABI) {
if (SizeInRegs > State.FreeRegs) {
State.FreeRegs = 0;
return false;
}
} else {
// The MCU psABI allows passing parameters in-reg even if there are
// earlier parameters that are passed on the stack. Also,
// it does not allow passing >8-byte structs in-register,
// even if there are 3 free registers available.
if (SizeInRegs > State.FreeRegs || SizeInRegs > 2)
return false;
}
State.FreeRegs -= SizeInRegs;
@ -1372,6 +1383,8 @@ void X86_32ABIInfo::computeInfo(CGFunctionInfo &FI) const {
State.FreeSSERegs = 6;
} else if (FI.getHasRegParm())
State.FreeRegs = FI.getRegParm();
else if (IsMCUABI)
State.FreeRegs = 3;
else
State.FreeRegs = DefaultNumRegisterParameters;
@ -1520,7 +1533,7 @@ bool X86_32TargetCodeGenInfo::isStructReturnInRegABI(
return true;
}
if (Triple.isOSDarwin())
if (Triple.isOSDarwin() || Triple.isEnvironmentIAMCU())
return true;
switch (Triple.getOS()) {

58
clang/test/CodeGen/x86_32-arguments-iamcu.c Normal file
View File

@ -0,0 +1,58 @@
// RUN: %clang_cc1 -w -triple i386-pc-elfiamcu -mfloat-abi soft -emit-llvm -o - %s | FileCheck %s
// CHECK-LABEL: define void @ints(i32 inreg %a, i32 inreg %b, i32 inreg %c, i32 %d)
void ints(int a, int b, int c, int d) {}
// CHECK-LABEL: define void @floats(float inreg %a, float inreg %b, float inreg %c, float %d)
void floats(float a, float b, float c, float d) {}
// CHECK-LABEL: define void @mixed(i32 inreg %a, float inreg %b, i32 inreg %c, float %d)
void mixed(int a, float b, int c, float d) {}
// CHECK-LABEL: define void @doubles(double inreg %d1, double %d2)
void doubles(double d1, double d2) {}
// CHECK-LABEL: define void @mixedDoubles(i32 inreg %a, double inreg %d1)
void mixedDoubles(int a, double d1) {}
typedef struct st4_t {
int a;
} st4_t;
typedef struct st5_t {
int a;
char b;
} st5_t;
typedef struct st12_t {
int a;
int b;
int c;
} st12_t;
// CHECK-LABEL: define void @smallStructs(i32 inreg %st1.coerce, i32 inreg %st2.coerce, i32 inreg %st3.coerce)
void smallStructs(st4_t st1, st4_t st2, st4_t st3) {}
// CHECK-LABEL: define void @paddedStruct(i32 inreg %i1, i32 inreg %st.coerce0, i32 inreg %st.coerce1, i32 %st4.0)
void paddedStruct(int i1, st5_t st, st4_t st4) {}
// CHECK-LABEL: define void @largeStruct(i32 %st.0, i32 %st.1, i32 %st.2)
void largeStruct(st12_t st) {}
// CHECK-LABEL: define void @largeStructMiddle(i32 inreg %i1, i32 %st.0, i32 %st.1, i32 %st.2, i32 inreg %i2, i32 inreg %i3)
void largeStructMiddle(int i1, st12_t st, int i2, int i3) {}
// CHECK-LABEL: define i32 @retSmallStruct(i32 inreg %r.coerce)
st4_t retSmallStruct(st4_t r) { return r; }
// CHECK-LABEL: define i64 @retPaddedStruct(i32 inreg %r.coerce0, i32 inreg %r.coerce1)
st5_t retPaddedStruct(st5_t r) { return r; }
// CHECK-LABEL: define void @retLargeStruct(%struct.st12_t* inreg noalias sret %agg.result, i32 inreg %i1, i32 %r.0, i32 %r.1, i32 %r.2)
st12_t retLargeStruct(int i1, st12_t r) { return r; }
// FIXME: We really shouldn't be marking this inreg. Right now the
// inreg gets ignored by the CG for varargs functions, but that's
// insane.
// CHECK-LABEL: define i32 @varArgs(i32 inreg %i1, ...)
int varArgs(int i1, ...) { return i1; }