aboutsummaryrefslogtreecommitdiffstats
path: root/lib/Target/X86/README-SSE.txt
diff options
context:
space:
mode:
authorPirama Arumuga Nainar <pirama@google.com>2015-04-10 21:22:52 +0000
committerGerrit Code Review <noreply-gerritcodereview@google.com>2015-04-10 21:23:04 +0000
commit31195f0bdca6ee2a5e72d07edf13e1d81206d949 (patch)
tree1b2c9792582e12f5af0b1512e3094425f0dc0df9 /lib/Target/X86/README-SSE.txt
parentc75239e6119d0f9a74c57099d91cbc9bde56bf33 (diff)
parent4c5e43da7792f75567b693105cc53e3f1992ad98 (diff)
downloadexternal_llvm-31195f0bdca6ee2a5e72d07edf13e1d81206d949.zip
external_llvm-31195f0bdca6ee2a5e72d07edf13e1d81206d949.tar.gz
external_llvm-31195f0bdca6ee2a5e72d07edf13e1d81206d949.tar.bz2
Merge "Update aosp/master llvm for rebase to r233350"
Diffstat (limited to 'lib/Target/X86/README-SSE.txt')
-rw-r--r--lib/Target/X86/README-SSE.txt78
1 files changed, 0 insertions, 78 deletions
diff --git a/lib/Target/X86/README-SSE.txt b/lib/Target/X86/README-SSE.txt
index 71329b0..e6896e8 100644
--- a/lib/Target/X86/README-SSE.txt
+++ b/lib/Target/X86/README-SSE.txt
@@ -93,36 +93,6 @@ The pattern isel got this one right.
//===---------------------------------------------------------------------===//
-SSE should implement 'select_cc' using 'emulated conditional moves' that use
-pcmp/pand/pandn/por to do a selection instead of a conditional branch:
-
-double %X(double %Y, double %Z, double %A, double %B) {
- %C = setlt double %A, %B
- %z = fadd double %Z, 0.0 ;; select operand is not a load
- %D = select bool %C, double %Y, double %z
- ret double %D
-}
-
-We currently emit:
-
-_X:
- subl $12, %esp
- xorpd %xmm0, %xmm0
- addsd 24(%esp), %xmm0
- movsd 32(%esp), %xmm1
- movsd 16(%esp), %xmm2
- ucomisd 40(%esp), %xmm1
- jb LBB_X_2
-LBB_X_1:
- movsd %xmm0, %xmm2
-LBB_X_2:
- movsd %xmm2, (%esp)
- fldl (%esp)
- addl $12, %esp
- ret
-
-//===---------------------------------------------------------------------===//
-
Lower memcpy / memset to a series of SSE 128 bit move instructions when it's
feasible.
@@ -787,25 +757,6 @@ cheaper to do fld1 than load from a constant pool for example, so
//===---------------------------------------------------------------------===//
-The X86 backend should be able to if-convert SSE comparisons like "ucomisd" to
-"cmpsd". For example, this code:
-
-double d1(double x) { return x == x ? x : x + x; }
-
-Compiles into:
-
-_d1:
- ucomisd %xmm0, %xmm0
- jnp LBB1_2
- addsd %xmm0, %xmm0
- ret
-LBB1_2:
- ret
-
-Also, the 'ret's should be shared. This is PR6032.
-
-//===---------------------------------------------------------------------===//
-
These should compile into the same code (PR6214): Perhaps instcombine should
canonicalize the former into the later?
@@ -858,35 +809,6 @@ doing a shuffle from v[1] to v[0] then a float store.
//===---------------------------------------------------------------------===//
-On SSE4 machines, we compile this code:
-
-define <2 x float> @test2(<2 x float> %Q, <2 x float> %R,
- <2 x float> *%P) nounwind {
- %Z = fadd <2 x float> %Q, %R
-
- store <2 x float> %Z, <2 x float> *%P
- ret <2 x float> %Z
-}
-
-into:
-
-_test2: ## @test2
-## BB#0:
- insertps $0, %xmm2, %xmm2
- insertps $16, %xmm3, %xmm2
- insertps $0, %xmm0, %xmm3
- insertps $16, %xmm1, %xmm3
- addps %xmm2, %xmm3
- movq %xmm3, (%rdi)
- movaps %xmm3, %xmm0
- pshufd $1, %xmm3, %xmm1
- ## kill: XMM1<def> XMM1<kill>
- ret
-
-The insertps's of $0 are pointless complex copies.
-
-//===---------------------------------------------------------------------===//
-
[UNSAFE FP]
void foo(double, double, double);