diff options
| author | Chris Lattner <sabre@nondot.org> | 2010-12-13 04:50:38 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2010-12-13 04:50:38 +0000 |
| commit | 7312a22ed63607e4ae7b0d9326e42358fd41e245 (patch) | |
| tree | 5c596e06052b978ad7a6634d4b6a97d97901e3df /lib/CodeGen/LiveStackAnalysis.cpp | |
| parent | f5198e7fe32704b25fc9d8b041a1d81cde1696b6 (diff) | |
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
Diffstat (limited to 'lib/CodeGen/LiveStackAnalysis.cpp')
0 files changed, 0 insertions, 0 deletions
