https://llvm.org/bugs/show_bug.cgi?id=30327
Bug ID: 30327
Summary: [InstCombine] should sub C, (zext i1) be canonicalized
to a select?
Product: libraries
Version: trunk
Hardware: PC
OS: All
Status: NEW
Severity: normal
Priority: P
Component: Scalar Optimizations
Assignee: [email protected]
Reporter: [email protected]
CC: [email protected]
Classification: Unclassified
These are logically equivalent:
unsigned sel(bool x) {
if (x)
return 54;
else
return 55;
}
unsigned add(bool x) {
return 55 - x;
}
But the optimized IR is:
define i32 @sel(i1 zeroext %x) {
%s = select i1 %x, i32 54, i32 55
ret i32 %s
}
define i32 @add(i1 zeroext %x) {
%conv = zext i1 %x to i32
%sub = sub nsw i32 55, %conv
ret i32 %sub
}
Which one is canonical?
--
You are receiving this mail because:
You are on the CC list for the bug.
_______________________________________________
llvm-bugs mailing list
[email protected]
http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-bugs
