llvm/test/CodeGen/X86/mmx-arg-passing.ll
Dale Johannesen 0488fb649a Massive rewrite of MMX:
The x86_mmx type is used for MMX intrinsics, parameters and
return values where these use MMX registers, and is also
supported in load, store, and bitcast.

Only the above operations generate MMX instructions, and optimizations
do not operate on or produce MMX intrinsics. 

MMX-sized vectors <2 x i32> etc. are lowered to XMM or split into
smaller pieces.  Optimizations may occur on these forms and the
result casted back to x86_mmx, provided the result feeds into a
previous existing x86_mmx operation.

The point of all this is prevent optimizations from introducing
MMX operations, which is unsafe due to the EMMS problem.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115243 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-30 23:57:10 +00:00

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1.0 KiB
LLVM

; RUN: llc < %s -mtriple=i386-apple-darwin -mattr=+mmx | grep mm0 | count 1
; RUN: llc < %s -mtriple=i386-apple-darwin -mattr=+mmx | grep esp | count 2
; RUN: llc < %s -mtriple=x86_64-apple-darwin -mattr=+mmx,+sse2 | grep xmm0
; RUN: llc < %s -mtriple=x86_64-apple-darwin -mattr=+mmx,+sse2 | grep rdi
; RUN: llc < %s -mtriple=x86_64-apple-darwin -mattr=+mmx,+sse2 | not grep movups
;
; On Darwin x86-32, v8i8, v4i16, v2i32 values are passed in MM[0-2].
; On Darwin x86-32, v1i64 values are passed in memory. In this example, they
; are never moved into an MM register at all.
; On Darwin x86-64, v8i8, v4i16, v2i32 values are passed in XMM[0-7].
; On Darwin x86-64, v1i64 values are passed in 64-bit GPRs.
@u1 = external global x86_mmx
define void @t1(x86_mmx %v1) nounwind {
store x86_mmx %v1, x86_mmx* @u1, align 8
ret void
}
@u2 = external global x86_mmx
define void @t2(<1 x i64> %v1) nounwind {
%tmp = bitcast <1 x i64> %v1 to x86_mmx
store x86_mmx %tmp, x86_mmx* @u2, align 8
ret void
}