llvm-6502/lib/Transforms
Chris Lattner 7312a22ed6 enhance the "change or icmp's into switch" xform to handle one value in an
'or sequence' that it doesn't understand.  This allows us to optimize
something insane like this:

int crud (unsigned char c, unsigned x)
 {
   if(((((((((( (int) c <= 32 ||
                    (int) c == 46) || (int) c == 44)
                  || (int) c == 58) || (int) c == 59) || (int) c == 60)
               || (int) c == 62) || (int) c == 34) || (int) c == 92)
            || (int) c == 39) != 0)
     foo();
 }

into:

define i32 @crud(i8 zeroext %c, i32 %x) nounwind ssp noredzone {
entry:
  %cmp = icmp ult i8 %c, 33
  br i1 %cmp, label %if.then, label %switch.early.test

switch.early.test:                                ; preds = %entry
  switch i8 %c, label %if.end [
    i8 39, label %if.then
    i8 44, label %if.then
    i8 58, label %if.then
    i8 59, label %if.then
    i8 60, label %if.then
    i8 62, label %if.then
    i8 46, label %if.then
    i8 92, label %if.then
    i8 34, label %if.then
  ]

by pulling the < comparison out ahead of the newly formed switch.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121680 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 04:50:38 +00:00
..
Hello Since the Hello pass is built as a loadable dynamic library, don't try to convert it to new-style registration yet. 2010-10-07 00:31:16 +00:00
InstCombine Generalize the and-icmp-select instcombine further by allowing selects of the form 2010-12-11 10:49:22 +00:00
Instrumentation Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which 2010-10-19 17:21:58 +00:00
IPO reapply r121100 with a tweak to constant fold ConstExprs with TargetData 2010-12-07 04:33:29 +00:00
Scalar simplify code and reduce indentation 2010-12-13 02:38:13 +00:00
Utils enhance the "change or icmp's into switch" xform to handle one value in an 2010-12-13 04:50:38 +00:00
Makefile Revert r100896 and around - this breaks the only mingw32 buildbot we have. 2010-04-15 19:51:42 +00:00