[llvm-commits] CVS: llvm/lib/Target/X86/README-SSE.txt README.txt

[Evan Cheng]

Changes in directory llvm/lib/Target/X86:

README-SSE.txt updated: 1.7 -> 1.8
README.txt updated: 1.143 -> 1.144
---
Log message:

These are done.

---
Diffs of the changes:  (+0 -69)

 README-SSE.txt |   58 ---------------------------------------------------------
 README.txt     |   11 ----------
 2 files changed, 69 deletions(-)


Index: llvm/lib/Target/X86/README-SSE.txt
diff -u llvm/lib/Target/X86/README-SSE.txt:1.7 llvm/lib/Target/X86/README-SSE.txt:1.8
--- llvm/lib/Target/X86/README-SSE.txt:1.7	Wed Oct 18 12:04:09 2006
+++ llvm/lib/Target/X86/README-SSE.txt	Fri Nov 10 16:03:35 2006
@@ -4,30 +4,6 @@
 
 //===---------------------------------------------------------------------===//
 
-There are serious issues folding loads into "scalar sse" intrinsics.  For
-example, this:
-
-float minss4( float x, float *y ) { 
-  return _mm_cvtss_f32(_mm_min_ss(_mm_set_ss(x),_mm_set_ss(*y)));
-}
-
-compiles to:
-
-_minss4:
-        subl $4, %esp
-        movl 12(%esp), %eax
-***     movss 8(%esp), %xmm0
-***     movss (%eax), %xmm1
-***     minss %xmm1, %xmm0
-        movss %xmm0, (%esp)
-        flds (%esp)
-        addl $4, %esp
-        ret
-
-Each operand of the minss is a load.  At least one should be folded!
-
-//===---------------------------------------------------------------------===//
-
 Expand libm rounding functions inline:  Significant speedups possible.
 http://gcc.gnu.org/ml/gcc-patches/2006-10/msg00909.html
 
@@ -165,17 +141,6 @@
 
 //===---------------------------------------------------------------------===//
 
-Should generate min/max for stuff like:
-
-void minf(float a, float b, float *X) {
-  *X = a <= b ? a : b;
-}
-
-Make use of floating point min / max instructions. Perhaps introduce ISD::FMIN
-and ISD::FMAX node types?
-
-//===---------------------------------------------------------------------===//
-
 Lower memcpy / memset to a series of SSE 128 bit move instructions when it's
 feasible.
 
@@ -225,29 +190,6 @@
 
 //===---------------------------------------------------------------------===//
 
-Better codegen for:
-
-void f(float a, float b, vector float * out) { *out = (vector float){ a, 0.0, 0.0, b}; }
-void f(float a, float b, vector float * out) { *out = (vector float){ a, b, 0.0, 0}; }
-
-For the later we generate:
-
-_f:
-        pxor %xmm0, %xmm0
-        movss 8(%esp), %xmm1
-        movaps %xmm0, %xmm2
-        unpcklps %xmm1, %xmm2
-        movss 4(%esp), %xmm1
-        unpcklps %xmm0, %xmm1
-        unpcklps %xmm2, %xmm1
-        movl 12(%esp), %eax
-        movaps %xmm1, (%eax)
-        ret
-
-This seems like it should use shufps, one for each of a & b.
-
-//===---------------------------------------------------------------------===//
-
 How to decide when to use the "floating point version" of logical ops? Here are
 some code fragments:
 


Index: llvm/lib/Target/X86/README.txt
diff -u llvm/lib/Target/X86/README.txt:1.143 llvm/lib/Target/X86/README.txt:1.144
--- llvm/lib/Target/X86/README.txt:1.143	Sun Oct 22 16:40:12 2006
+++ llvm/lib/Target/X86/README.txt	Fri Nov 10 16:03:35 2006
@@ -232,17 +232,6 @@
 
 //===---------------------------------------------------------------------===//
 
-Should generate min/max for stuff like:
-
-void minf(float a, float b, float *X) {
-  *X = a <= b ? a : b;
-}
-
-Make use of floating point min / max instructions. Perhaps introduce ISD::FMIN
-and ISD::FMAX node types?
-
-//===---------------------------------------------------------------------===//
-
 The first BB of this code:
 
 declare bool %foo()