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llvm-project/llvm/test/CodeGen/X86/inalloca-stdcall.ll

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Implement inalloca codegen for x86 with the new inalloca design Calls with inalloca are lowered by skipping all stores for arguments passed in memory and the initial stack adjustment to allocate argument memory. Now the frontend is responsible for the memory layout, and the backend doesn't have to do any work. As a result these changes are pretty minimal. Reviewers: echristo Differential Revision: http://llvm-reviews.chandlerc.com/D2637 llvm-svn: 200596
2014-02-01 07:50:57 +08:00
; RUN: llc < %s -mtriple=i686-pc-win32 | FileCheck %s
%Foo = type { i32, i32 }
declare x86_stdcallcc void @f(%Foo* inalloca %a)
declare x86_stdcallcc void @i(i32 %a)
define void @g() {
IR: Change inalloca's grammar a bit The grammar for LLVM IR is not well specified in any document but seems to obey the following rules: - Attributes which have parenthesized arguments are never preceded by commas. This form of attribute is the only one which ever has optional arguments. However, not all of these attributes support optional arguments: 'thread_local' supports an optional argument but 'addrspace' does not. Interestingly, 'addrspace' is documented as being a "qualifier". What constitutes a qualifier? I cannot find a definition. - Some attributes use a space between the keyword and the value. Examples of this form are 'align' and 'section'. These are always preceded by a comma. - Otherwise, the attribute has no argument. These attributes do not have a preceding comma. Sometimes an attribute goes before the instruction, between the instruction and it's type, or after it's type. 'atomicrmw' has 'volatile' between the instruction and the type while 'call' has 'tail' preceding the instruction. With all this in mind, it seems most consistent for 'inalloca' on an 'inalloca' instruction to occur before between the instruction and the type. Unlike the current formulation, there would be no preceding comma. The combination 'alloca inalloca' doesn't look particularly appetizing, perhaps a better spelling of 'inalloca' is down the road. llvm-svn: 203376
2014-03-09 14:41:58 +08:00
%b = alloca inalloca %Foo
Implement inalloca codegen for x86 with the new inalloca design Calls with inalloca are lowered by skipping all stores for arguments passed in memory and the initial stack adjustment to allocate argument memory. Now the frontend is responsible for the memory layout, and the backend doesn't have to do any work. As a result these changes are pretty minimal. Reviewers: echristo Differential Revision: http://llvm-reviews.chandlerc.com/D2637 llvm-svn: 200596
2014-02-01 07:50:57 +08:00
; CHECK: movl $8, %eax
; CHECK: calll __chkstk
; CHECK: movl %[[REG:[^,]*]], %esp
%f1 = getelementptr %Foo* %b, i32 0, i32 0
%f2 = getelementptr %Foo* %b, i32 0, i32 1
store i32 13, i32* %f1
store i32 42, i32* %f2
; CHECK: movl $13, (%[[REG]])
; CHECK: movl $42, 4(%[[REG]])
call x86_stdcallcc void @f(%Foo* inalloca %b)
; CHECK: calll _f@8
; CHECK-NOT: %esp
; CHECK: subl $4, %esp
; CHECK: calll _i@4
call x86_stdcallcc void @i(i32 0)
ret void
}