[llvm-commits] [llvm] r130385 - /llvm/trunk/lib/Target/X86/README.txt

[Chris Lattner]

Author: lattner
Date: Thu Apr 28 00:33:16 2011
New Revision: 130385

URL: http://llvm.org/viewvc/llvm-project?rev=130385&view=rev
Log:
move PR9803 to this readme.

Modified:
    llvm/trunk/lib/Target/X86/README.txt

Modified: llvm/trunk/lib/Target/X86/README.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/README.txt?rev=130385&r1=130384&r2=130385&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/README.txt (original)
+++ llvm/trunk/lib/Target/X86/README.txt Thu Apr 28 00:33:16 2011
@@ -2032,3 +2032,31 @@
 with -ffast-math.
 
 //===---------------------------------------------------------------------===//
+
+This function (from PR9803):
+
+int clamp2(int a) {
+        if (a > 5)
+                a = 5;
+        if (a < 0) 
+                return 0;
+        return a;
+}
+
+Compiles to:
+
+_clamp2:                                ## @clamp2
+        pushq   %rbp
+        movq    %rsp, %rbp
+        cmpl    $5, %edi
+        movl    $5, %ecx
+        cmovlel %edi, %ecx
+        testl   %ecx, %ecx
+        movl    $0, %eax
+        cmovnsl %ecx, %eax
+        popq    %rbp
+        ret
+
+The move of 0 could be scheduled above the test to make it is xor reg,reg.
+
+//===---------------------------------------------------------------------===//