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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28787 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 29 insertions, 0 deletions

diff --git a/lib/Target/X86/README-SSE.txt b/lib/Target/X86/README-SSE.txt
index ecf846c281..5b741e6f7a 100644
--- a/lib/Target/X86/README-SSE.txt
+++ b/lib/Target/X86/README-SSE.txt
@@ -664,3 +664,32 @@ e.g. SSE select using and, andnot, or. Various SSE compare translations.
 //===---------------------------------------------------------------------===//
 
 Add hooks to commute some CMPP operations.
+
+//===---------------------------------------------------------------------===//
+
+Implement some missing insert/extract element operations without going through
+the stack.  Testcase here:
+CodeGen/X86/vec_ins_extract.ll
+corresponds to this C code:
+
+typedef float vectorfloat __attribute__((vector_size(16)));
+void test(vectorfloat *F, float f) {
+  vectorfloat G = *F + *F;
+  *((float*)&G) = f;
+  *F = G + G;
+}
+void test2(vectorfloat *F, float f) {
+  vectorfloat G = *F + *F;
+  ((float*)&G)[2] = f;
+  *F = G + G;
+}
+void test3(vectorfloat *F, float *f) {
+  vectorfloat G = *F + *F;
+  *f = ((float*)&G)[2];
+}
+void test4(vectorfloat *F, float *f) {
+  vectorfloat G = *F + *F;
+  *f = *((float*)&G);
+}
+
+//===---------------------------------------------------------------------===//