6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-02-19 23:29:20 +00:00
Code Issues Projects Releases Wiki Activity

TODO--

Browse Source 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106102 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Benjamin Kramer 2010-06-16 15:47:00 +00:00
parent ea9ca0236d
commit 0f471e018f
1 changed files with 0 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
lib/Target/README.txt
View File

@ -1439,33 +1439,6 @@ This pattern repeats several times, basically doing:
//===---------------------------------------------------------------------===//
186.crafty contains this interesting pattern:
%77 = call i8* @strstr(i8* getelementptr ([6 x i8]* @"\01LC5", i32 0, i32 0),
i8* %30)
%phitmp648 = icmp eq i8* %77, getelementptr ([6 x i8]* @"\01LC5", i32 0, i32 0)
br i1 %phitmp648, label %bb70, label %bb76
bb70: ; preds = %OptionMatch.exit91, %bb69
%78 = call i32 @strlen(i8* %30) nounwind readonly align 1 ; <i32> [#uses=1]
This is basically:
cststr = "abcdef";
if (strstr(cststr, P) == cststr) {
x = strlen(P);
...
The strstr call would be significantly cheaper written as:
cststr = "abcdef";
if (memcmp(P, str, strlen(P)))
x = strlen(P);
This is memcmp+strlen instead of strstr. This also makes the strlen fully
redundant.
//===---------------------------------------------------------------------===//
186.crafty also contains this code:
%1906 = call i32 @strlen(i8* getelementptr ([32 x i8]* @pgn_event, i32 0,i32 0))