Changes in directory llvm/lib/Target/X86:
README.txt updated: 1.136 -> 1.137
---
Log message:
add a note
---
Diffs of the changes: (+16 -0)
README.txt | 16 ++++++++++++++++
1 files changed, 16 insertions(+)
Index: llvm/lib/Target/X86/README.txt
diff -u llvm/lib/Target/X86/README.txt:1.136
llvm/lib/Target/X86/README.txt:1.137
--- llvm/lib/Target/X86/README.txt:1.136 Mon Sep 18 00:36:54 2006
+++ llvm/lib/Target/X86/README.txt Wed Sep 20 01:32:10 2006
@@ -734,3 +734,19 @@
addl $12, %esp
The add\sub pair is really unneeded here.
+
+//===---------------------------------------------------------------------===//
+
+We generate really bad code in some cases due to lowering SETCC/SELECT at
+legalize time, which prevents the post-legalize dag combine pass from
+understanding the code. As a silly example, this prevents us from folding
+stuff like this:
+
+bool %test(ulong %x) {
+ %tmp = setlt ulong %x, 4294967296
+ ret bool %tmp
+}
+
+into x.h == 0
+
+
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