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Improve implementation of __masked_store_blend_64() for AVX target by doing two 8-wide 32-bit blends rather than serializing. Fixes issue #29

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Matt Pharr
2011-06-28 20:52:06 -07:00
parent ce7978ae74
commit 86de910ecd
2 changed files with 48 additions and 6 deletions
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1
.gitignore vendored
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@@ -4,3 +4,4 @@ depend
ispc
ispc_test
objs
docs/doxygen

53
stdlib-avx.ll
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@@ -525,12 +525,53 @@ define void @__masked_store_blend_32(<8 x i32>* nocapture, <8 x i32>,
}
define void @__masked_store_blend_64(<8 x i64>* nocapture, <8 x i64>,
<8 x i32>) nounwind alwaysinline {
; always just serialize it
; FIXME: should implement the "do two 32-bit masked stores" stuff that
; other targets do...
call void @__masked_store_64(<8 x i64>* nocapture %0, <8 x i64> %1, <8 x i32> %2)
define void @__masked_store_blend_64(<8 x i64>* nocapture %ptr, <8 x i64> %new,
<8 x i32> %i32mask) nounwind alwaysinline {
%oldValue = load <8 x i64>* %ptr, align 8
%mask = bitcast <8 x i32> %i32mask to <8 x float>
; Do 4x64-bit blends by doing two <8 x i32> blends, where the <8 x i32> values
; are actually bitcast <4 x i64> values
;
; set up the first four 64-bit values
%old01 = shufflevector <8 x i64> %oldValue, <8 x i64> undef,
<4 x i32> <i32 0, i32 1, i32 2, i32 3>
%old01f = bitcast <4 x i64> %old01 to <8 x float>
%new01 = shufflevector <8 x i64> %new, <8 x i64> undef,
<4 x i32> <i32 0, i32 1, i32 2, i32 3>
%new01f = bitcast <4 x i64> %new01 to <8 x float>
; compute mask--note that the indices are all doubled-up
%mask01 = shufflevector <8 x float> %mask, <8 x float> undef,
<8 x i32> <i32 0, i32 0, i32 1, i32 1,
i32 2, i32 2, i32 3, i32 3>
; and blend them
%result01f = call <8 x float> @llvm.x86.avx.blendvps(<8 x float> %old01f,
<8 x float> %new01f,
<8 x float> %mask01)
%result01 = bitcast <8 x float> %result01f to <4 x i64>
; and again
%old23 = shufflevector <8 x i64> %oldValue, <8 x i64> undef,
<4 x i32> <i32 4, i32 5, i32 6, i32 7>
%old23f = bitcast <4 x i64> %old23 to <8 x float>
%new23 = shufflevector <8 x i64> %new, <8 x i64> undef,
<4 x i32> <i32 4, i32 5, i32 6, i32 7>
%new23f = bitcast <4 x i64> %new23 to <8 x float>
; compute mask--note that the values are doubled-up...
%mask23 = shufflevector <8 x float> %mask, <8 x float> undef,
<8 x i32> <i32 4, i32 4, i32 5, i32 5,
i32 6, i32 6, i32 7, i32 7>
; and blend them
%result23f = call <8 x float> @llvm.x86.avx.blendvps(<8 x float> %old23f,
<8 x float> %new23f,
<8 x float> %mask23)
%result23 = bitcast <8 x float> %result23f to <4 x i64>
; reconstruct the final <8 x i64> vector
%final = shufflevector <4 x i64> %result01, <4 x i64> %result23,
<8 x i32> <i32 0, i32 1, i32 2, i32 3,
i32 4, i32 5, i32 6, i32 7>
store <8 x i64> %final, <8 x i64> * %ptr, align 8
ret void
}