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c90bd4a882
Summary: I had difficulty finding tests for the N32 and N64 ABI so I've added a collection of calling convention tests based on the document MIPS ABIs Described (MD00305), the MIPSpro N32 Handbook, and the SYSV ABI. Where the documents/implementations disagree, I've used GCC to resolve the conflict. A few interesting details: * For N32, LLVM uses 64-bit pointers when saving $ra despite pointers being 32-bit. I've yet to find a supporting statement in the ABI documentation but the current behaviour matches GCC. * For O32, the non-variable portion of a varargs argument list is also subject to the rule that floating-point is passed via GPR's (on N32/N64 only the variable portion is subject to this rule). This agrees with GCC's behaviour and the SYSV ABI but contradicts part of the MIPSpro N32 Handbook which talks about O32's behaviour. * The N32 implementation has the wrong callee-saved register list. (I already have a fix for this but will commit it as a follow-up). I've left RUN-TODO lines in for O32 on MIPS64. I don't plan to support this case for now but we should revisit it. Reviewers: matheusalmeida, vmedic Reviewed By: matheusalmeida Differential Revision: http://reviews.llvm.org/D3339 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206370 91177308-0d34-0410-b5e6-96231b3b80d8
40 lines
1.7 KiB
LLVM
40 lines
1.7 KiB
LLVM
; RUN: llc -march=mips < %s | FileCheck --check-prefix=ALL --check-prefix=O32 %s
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; RUN: llc -march=mipsel < %s | FileCheck --check-prefix=ALL --check-prefix=O32 %s
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; RUN-TODO: llc -march=mips64 -mattr=-n64,+o32 < %s | FileCheck --check-prefix=ALL --check-prefix=O32 %s
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; RUN-TODO: llc -march=mips64el -mattr=-n64,+o32 < %s | FileCheck --check-prefix=ALL --check-prefix=O32 %s
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; RUN: llc -march=mips64 -mattr=-n64,+n32 < %s | FileCheck --check-prefix=ALL --check-prefix=N32 %s
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; RUN: llc -march=mips64el -mattr=-n64,+n32 < %s | FileCheck --check-prefix=ALL --check-prefix=N32 %s
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; RUN: llc -march=mips64 -mattr=-n64,+n64 < %s | FileCheck --check-prefix=ALL --check-prefix=N64 %s
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; RUN: llc -march=mips64el -mattr=-n64,+n64 < %s | FileCheck --check-prefix=ALL --check-prefix=N64 %s
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; Test that O32 correctly reserved space for the four arguments, even when
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; there aren't any as per section 5 of MD00305 (MIPS ABIs Described).
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declare void @foo() nounwind;
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define void @reserved_space() nounwind {
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entry:
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tail call void @foo()
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ret void
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}
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; ALL-LABEL: reserved_space:
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; O32: addiu $sp, $sp, -24
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; O32: sw $ra, 20($sp)
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; O32: lw $ra, 20($sp)
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; O32: addiu $sp, $sp, 24
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; Despite pointers being 32-bit wide on N32, the return pointer is saved as a
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; 64-bit pointer. I've yet to find a documentation reference for this quirk but
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; this behaviour matches GCC so I have considered it to be correct.
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; N32: addiu $sp, $sp, -16
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; N32: sd $ra, 8($sp)
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; N32: ld $ra, 8($sp)
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; N32: addiu $sp, $sp, 16
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; N64: daddiu $sp, $sp, -16
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; N64: sd $ra, 8($sp)
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; N64: ld $ra, 8($sp)
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; N64: daddiu $sp, $sp, 16
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