[llvm] r200561 - [ms-cxxabi] Add a new calling convention that swaps 'this' and 'sret'
Reid Kleckner
reid at kleckner.net
Fri Jan 31 09:41:22 PST 2014
Author: rnk
Date: Fri Jan 31 11:41:22 2014
New Revision: 200561
URL: http://llvm.org/viewvc/llvm-project?rev=200561&view=rev
Log:
[ms-cxxabi] Add a new calling convention that swaps 'this' and 'sret'
MSVC always places the 'this' parameter for a method first. The
implicit 'sret' pointer for methods always comes second. We already
implement this for __thiscall by putting sret parameters on the stack,
but __cdecl methods require putting both parameters on the stack in
opposite order.
Using a special calling convention allows frontends to keep the sret
parameter first, which avoids breaking lots of assumptions in LLVM and
Clang.
Fixes PR15768 with the corresponding change in Clang.
Reviewers: ributzka, majnemer
Differential Revision: http://llvm-reviews.chandlerc.com/D2663
Added:
llvm/trunk/test/CodeGen/X86/cdecl-method-return.ll
Modified:
llvm/trunk/docs/BitCodeFormat.rst
llvm/trunk/docs/CodeGenerator.rst
llvm/trunk/include/llvm/IR/CallingConv.h
llvm/trunk/lib/AsmParser/LLLexer.cpp
llvm/trunk/lib/AsmParser/LLParser.cpp
llvm/trunk/lib/AsmParser/LLToken.h
llvm/trunk/lib/IR/AsmWriter.cpp
llvm/trunk/lib/Target/X86/X86CallingConv.h
llvm/trunk/lib/Target/X86/X86CallingConv.td
Modified: llvm/trunk/docs/BitCodeFormat.rst
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/BitCodeFormat.rst?rev=200561&r1=200560&r2=200561&view=diff
==============================================================================
--- llvm/trunk/docs/BitCodeFormat.rst (original)
+++ llvm/trunk/docs/BitCodeFormat.rst Fri Jan 31 11:41:22 2014
@@ -746,6 +746,8 @@ function. The operand fields are:
* ``arm_apcscc``: code 66
* ``arm_aapcscc``: code 67
* ``arm_aapcs_vfpcc``: code 68
+ * ``x86_thiscallcc``: code 70
+ * ``x86_cdeclmethodcc``: code 80
* isproto*: Non-zero if this entry represents a declaration rather than a
definition
Modified: llvm/trunk/docs/CodeGenerator.rst
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/CodeGenerator.rst?rev=200561&r1=200560&r2=200561&view=diff
==============================================================================
--- llvm/trunk/docs/CodeGenerator.rst (original)
+++ llvm/trunk/docs/CodeGenerator.rst Fri Jan 31 11:41:22 2014
@@ -2145,6 +2145,10 @@ The following target-specific calling co
others via stack. Callee is responsible for stack cleaning. This convention is
used by MSVC by default for methods in its ABI (CC ID = 70).
+* **X86_CDeclMethod** --- Identical to the standard x86_32 C calling convention,
+ except that an sret paramter, if present, is placed on the stack after the
+ second parameter, which must an integer or pointer. (CC ID = 80).
+
.. _X86 addressing mode:
Representing X86 addressing modes in MachineInstrs
Modified: llvm/trunk/include/llvm/IR/CallingConv.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/IR/CallingConv.h?rev=200561&r1=200560&r2=200561&view=diff
==============================================================================
--- llvm/trunk/include/llvm/IR/CallingConv.h (original)
+++ llvm/trunk/include/llvm/IR/CallingConv.h Fri Jan 31 11:41:22 2014
@@ -137,7 +137,13 @@ namespace CallingConv {
/// convention differs from the more common \c X86_64_SysV convention
/// in a number of ways, most notably in that XMM registers used to pass
/// arguments are shadowed by GPRs, and vice versa.
- X86_64_Win64 = 79
+ X86_64_Win64 = 79,
+
+ /// \brief The calling convention used for __cdecl methods on win32.
+ /// Differs from the C calling convention only in that the order of the
+ /// first parameter and the sret parameter are swapped.
+ X86_CDeclMethod = 80
+
};
} // End CallingConv namespace
Modified: llvm/trunk/lib/AsmParser/LLLexer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/AsmParser/LLLexer.cpp?rev=200561&r1=200560&r2=200561&view=diff
==============================================================================
--- llvm/trunk/lib/AsmParser/LLLexer.cpp (original)
+++ llvm/trunk/lib/AsmParser/LLLexer.cpp Fri Jan 31 11:41:22 2014
@@ -550,6 +550,7 @@ lltok::Kind LLLexer::LexIdentifier() {
KEYWORD(x86_stdcallcc);
KEYWORD(x86_fastcallcc);
KEYWORD(x86_thiscallcc);
+ KEYWORD(x86_cdeclmethodcc);
KEYWORD(arm_apcscc);
KEYWORD(arm_aapcscc);
KEYWORD(arm_aapcs_vfpcc);
Modified: llvm/trunk/lib/AsmParser/LLParser.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/AsmParser/LLParser.cpp?rev=200561&r1=200560&r2=200561&view=diff
==============================================================================
--- llvm/trunk/lib/AsmParser/LLParser.cpp (original)
+++ llvm/trunk/lib/AsmParser/LLParser.cpp Fri Jan 31 11:41:22 2014
@@ -1357,6 +1357,7 @@ bool LLParser::ParseOptionalDLLStorageCl
/// ::= 'x86_stdcallcc'
/// ::= 'x86_fastcallcc'
/// ::= 'x86_thiscallcc'
+/// ::= 'x86_cdeclmethodcc'
/// ::= 'arm_apcscc'
/// ::= 'arm_aapcscc'
/// ::= 'arm_aapcs_vfpcc'
@@ -1382,6 +1383,7 @@ bool LLParser::ParseOptionalCallingConv(
case lltok::kw_x86_stdcallcc: CC = CallingConv::X86_StdCall; break;
case lltok::kw_x86_fastcallcc: CC = CallingConv::X86_FastCall; break;
case lltok::kw_x86_thiscallcc: CC = CallingConv::X86_ThisCall; break;
+ case lltok::kw_x86_cdeclmethodcc:CC = CallingConv::X86_CDeclMethod; break;
case lltok::kw_arm_apcscc: CC = CallingConv::ARM_APCS; break;
case lltok::kw_arm_aapcscc: CC = CallingConv::ARM_AAPCS; break;
case lltok::kw_arm_aapcs_vfpcc:CC = CallingConv::ARM_AAPCS_VFP; break;
Modified: llvm/trunk/lib/AsmParser/LLToken.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/AsmParser/LLToken.h?rev=200561&r1=200560&r2=200561&view=diff
==============================================================================
--- llvm/trunk/lib/AsmParser/LLToken.h (original)
+++ llvm/trunk/lib/AsmParser/LLToken.h Fri Jan 31 11:41:22 2014
@@ -85,7 +85,7 @@ namespace lltok {
kw_cc, kw_ccc, kw_fastcc, kw_coldcc,
kw_intel_ocl_bicc,
- kw_x86_stdcallcc, kw_x86_fastcallcc, kw_x86_thiscallcc,
+ kw_x86_stdcallcc, kw_x86_fastcallcc, kw_x86_thiscallcc, kw_x86_cdeclmethodcc,
kw_arm_apcscc, kw_arm_aapcscc, kw_arm_aapcs_vfpcc,
kw_msp430_intrcc,
kw_ptx_kernel, kw_ptx_device,
Modified: llvm/trunk/lib/IR/AsmWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/AsmWriter.cpp?rev=200561&r1=200560&r2=200561&view=diff
==============================================================================
--- llvm/trunk/lib/IR/AsmWriter.cpp (original)
+++ llvm/trunk/lib/IR/AsmWriter.cpp Fri Jan 31 11:41:22 2014
@@ -78,6 +78,7 @@ static void PrintCallingConv(unsigned cc
case CallingConv::X86_StdCall: Out << "x86_stdcallcc"; break;
case CallingConv::X86_FastCall: Out << "x86_fastcallcc"; break;
case CallingConv::X86_ThisCall: Out << "x86_thiscallcc"; break;
+ case CallingConv::X86_CDeclMethod:Out << "x86_cdeclmethodcc"; break;
case CallingConv::Intel_OCL_BI: Out << "intel_ocl_bicc"; break;
case CallingConv::ARM_APCS: Out << "arm_apcscc"; break;
case CallingConv::ARM_AAPCS: Out << "arm_aapcscc"; break;
Modified: llvm/trunk/lib/Target/X86/X86CallingConv.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86CallingConv.h?rev=200561&r1=200560&r2=200561&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86CallingConv.h (original)
+++ llvm/trunk/lib/Target/X86/X86CallingConv.h Fri Jan 31 11:41:22 2014
@@ -29,6 +29,33 @@ inline bool CC_X86_AnyReg_Error(unsigned
return false;
}
+inline bool CC_X86_CDeclMethod_SRet(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
+ CCValAssign::LocInfo &LocInfo,
+ ISD::ArgFlagsTy &ArgFlags, CCState &State) {
+ // Swap the order of the first two parameters if the first parameter is sret.
+ if (ArgFlags.isSRet()) {
+ assert(ValNo == 0);
+ assert(ValVT == MVT::i32);
+ State.AllocateStack(8, 4);
+ State.addLoc(CCValAssign::getCustomMem(ValNo, ValVT, 4, LocVT, LocInfo));
+
+ // Indicate that we need to swap the order of the first and second
+ // parameters by "allocating" register zero. There are no register
+ // parameters with cdecl methods, so we can use this to communicate to the
+ // next call.
+ State.AllocateReg(1);
+ return true;
+ } else if (ValNo == 1 && State.isAllocated(1)) {
+ assert(ValVT == MVT::i32 && "non-i32-sized this param unsupported");
+ // Stack was already allocated while processing sret.
+ State.addLoc(CCValAssign::getCustomMem(ValNo, ValVT, 0, LocVT, LocInfo));
+ return true;
+ }
+
+ // All other args use the C calling convention.
+ return false;
+}
+
} // End llvm namespace
#endif
Modified: llvm/trunk/lib/Target/X86/X86CallingConv.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86CallingConv.td?rev=200561&r1=200560&r2=200561&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86CallingConv.td (original)
+++ llvm/trunk/lib/Target/X86/X86CallingConv.td Fri Jan 31 11:41:22 2014
@@ -485,6 +485,15 @@ def CC_X86_32_ThisCall_Win : CallingConv
CCDelegateTo<CC_X86_32_ThisCall_Common>
]>;
+def CC_X86_CDeclMethod : CallingConv<[
+ // Promote i8/i16 arguments to i32.
+ CCIfType<[i8, i16], CCPromoteToType<i32>>,
+
+ CCCustom<"CC_X86_CDeclMethod_SRet">,
+
+ CCDelegateTo<CC_X86_32_Common>
+]>;
+
def CC_X86_32_ThisCall : CallingConv<[
CCIfSubtarget<"isTargetCygMing()", CCDelegateTo<CC_X86_32_ThisCall_Mingw>>,
CCDelegateTo<CC_X86_32_ThisCall_Win>
@@ -574,6 +583,7 @@ def CC_Intel_OCL_BI : CallingConv<[
def CC_X86_32 : CallingConv<[
CCIfCC<"CallingConv::X86_FastCall", CCDelegateTo<CC_X86_32_FastCall>>,
CCIfCC<"CallingConv::X86_ThisCall", CCDelegateTo<CC_X86_32_ThisCall>>,
+ CCIfCC<"CallingConv::X86_CDeclMethod", CCDelegateTo<CC_X86_CDeclMethod>>,
CCIfCC<"CallingConv::Fast", CCDelegateTo<CC_X86_32_FastCC>>,
CCIfCC<"CallingConv::GHC", CCDelegateTo<CC_X86_32_GHC>>,
CCIfCC<"CallingConv::HiPE", CCDelegateTo<CC_X86_32_HiPE>>,
Added: llvm/trunk/test/CodeGen/X86/cdecl-method-return.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/cdecl-method-return.ll?rev=200561&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/cdecl-method-return.ll (added)
+++ llvm/trunk/test/CodeGen/X86/cdecl-method-return.ll Fri Jan 31 11:41:22 2014
@@ -0,0 +1,69 @@
+; RUN: llc < %s -mtriple=i686-pc-win32 | FileCheck %s
+
+; The sret flag causes the first two parameters to be reordered on the stack.
+
+define x86_cdeclmethodcc void @foo(i32* sret %dst, i32* %src) {
+ %v = load i32* %src
+ store i32 %v, i32* %dst
+ ret void
+}
+
+; CHECK-LABEL: _foo:
+; CHECK: movl 8(%esp), %[[dst:[^ ]*]]
+; CHECK: movl 4(%esp), %[[src:[^ ]*]]
+; CHECK: movl (%[[src]]), %[[v:[^ ]*]]
+; CHECK: movl %[[v]], (%[[dst]])
+; CHECK: retl
+
+define i32 @bar() {
+ %src = alloca i32
+ %dst = alloca i32
+ store i32 42, i32* %src
+ call x86_cdeclmethodcc void @foo(i32* sret %dst, i32* %src)
+ %v = load i32* %dst
+ ret i32 %v
+}
+
+; CHECK-LABEL: _bar:
+; CHECK: movl $42, [[src:[^,]*]]
+; CHECK: leal [[src]], %[[reg:[^ ]*]]
+; CHECK: movl %[[reg]], (%esp)
+; CHECK: leal [[dst:[^,]*]], %[[reg:[^ ]*]]
+; CHECK: movl %[[reg]], 4(%esp)
+; CHECK: calll _foo
+; CHECK: movl [[dst]], %eax
+; CHECK: retl
+
+; If we don't have the sret flag, parameters are not reordered.
+
+define x86_cdeclmethodcc void @baz(i32* %dst, i32* %src) {
+ %v = load i32* %src
+ store i32 %v, i32* %dst
+ ret void
+}
+
+; CHECK-LABEL: _baz:
+; CHECK: movl 4(%esp), %[[dst:[^ ]*]]
+; CHECK: movl 8(%esp), %[[src:[^ ]*]]
+; CHECK: movl (%[[src]]), %[[v:[^ ]*]]
+; CHECK: movl %[[v]], (%[[dst]])
+; CHECK: retl
+
+define i32 @qux() {
+ %src = alloca i32
+ %dst = alloca i32
+ store i32 42, i32* %src
+ call x86_cdeclmethodcc void @baz(i32* %dst, i32* %src)
+ %v = load i32* %dst
+ ret i32 %v
+}
+
+; CHECK-LABEL: _qux:
+; CHECK: movl $42, [[src:[^,]*]]
+; CHECK: leal [[src]], %[[reg:[^ ]*]]
+; CHECK: movl %[[reg]], 4(%esp)
+; CHECK: leal [[dst:[^,]*]], %[[reg:[^ ]*]]
+; CHECK: movl %[[reg]], (%esp)
+; CHECK: calll _baz
+; CHECK: movl [[dst]], %eax
+; CHECK: retl
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