Another entry
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27786 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/README.txt b/lib/Target/X86/README.txt
index 33be39e..39a4407 100644
--- a/lib/Target/X86/README.txt
+++ b/lib/Target/X86/README.txt
@@ -961,3 +961,38 @@
to three-address transformation.
It also exposes some other problems. See MOV32ri -3 and the spills.
+
+//===---------------------------------------------------------------------===//
+
+http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25500
+
+LLVM is producing bad code.
+
+LBB_main_4: # cond_true44
+ addps %xmm1, %xmm2
+ subps %xmm3, %xmm2
+ movaps (%ecx), %xmm4
+ movaps %xmm2, %xmm1
+ addps %xmm4, %xmm1
+ addl $16, %ecx
+ incl %edx
+ cmpl $262144, %edx
+ movaps %xmm3, %xmm2
+ movaps %xmm4, %xmm3
+ jne LBB_main_4 # cond_true44
+
+There are two problems. 1) No need to two loop induction variables. We can
+compare against 262144 * 16. 2) Poor register allocation decisions. We should
+be able eliminate one of the movaps:
+
+ addps %xmm1, %xmm2
+ subps %xmm3, %xmm2
+ movaps (%ecx), %xmm4
+ movaps %xmm2, %xmm2 <=== Eliminate!
+ addps %xmm4, %xmm2
+ addl $16, %ecx
+ incl %edx
+ cmpl $262144, %edx
+ movaps %xmm3, %xmm1
+ movaps %xmm4, %xmm3
+ jne LBB_main_4 # cond_true44