https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99405
Bug ID: 99405
Summary: Rotate with mask not optimized on x86 for QI/HImode
rotates
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: enhancement
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: jakub at gcc dot gnu.org
CC: jakub at gcc dot gnu.org, unlvsur at live dot com
Depends on: 99396
Target Milestone: ---
+++ This bug was initially created as a clone of Bug #99396 +++
In
unsigned char f1 (unsigned char x, unsigned y) { return (x << (y & 7)) | (x >>
(-y & 7)); }
unsigned short f2 (unsigned short x, unsigned y) { return (x << (y & 15)) | (x
>> (-y & 15)); }
unsigned int f3 (unsigned int x, unsigned y) { return (x << (y & 31)) | (x >>
(-y & 31)); }
unsigned char f4 (unsigned char x, unsigned y) { return (x >> (y & 7)) | (x <<
(-y & 7)); }
unsigned short f5 (unsigned short x, unsigned y) { return (x >> (y & 15)) | (x
<< (-y & 15)); }
unsigned int f6 (unsigned int x, unsigned y) { return (x >> (y & 31)) | (x <<
(-y & 31)); }
unsigned char f7 (unsigned char x, unsigned char y) { unsigned char v = y & 7;
unsigned char w = -y & 7; return (x << v) | (x >> w); }
unsigned short f8 (unsigned short x, unsigned char y) { unsigned char v = y &
15; unsigned char w = -y & 15; return (x << v) | (x >> w); }
unsigned int f9 (unsigned int x, unsigned char y) { unsigned char v = y & 31;
unsigned char w = -y & 31; return (x << v) | (x >> w); }
unsigned char f10 (unsigned char x, unsigned char y) { unsigned char v = y & 7;
unsigned char w = -y & 7; return (x >> v) | (x << w); }
unsigned short f11 (unsigned short x, unsigned char y) { unsigned char v = y &
15; unsigned char w = -y & 15; return (x >> v) | (x << w); }
unsigned int f12 (unsigned int x, unsigned char y) { unsigned char v = y & 31;
unsigned char w = -y & 31; return (x >> v) | (x << w); }
#ifdef __x86_64__
unsigned long long f13 (unsigned long long x, unsigned y) { return (x << (y &
63)) | (x >> (-y & 63)); }
unsigned long long f14 (unsigned long long x, unsigned y) { return (x >> (y &
63)) | (x << (-y & 63)); }
unsigned long long f15 (unsigned long long x, unsigned char y) { unsigned char
v = y & 63; unsigned char w = -y & 63; return (x << v) | (x >> w); }
unsigned long long f16 (unsigned long long x, unsigned char y) { unsigned char
v = y & 63; unsigned char w = -y & 63; return (x >> v) | (x << w); }
#endif
we don't optimize away the and instructions in f{1,2,4,5,7,8,10,11}.
Referenced Bugs:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99396
[Bug 99396] std::rotl and std::rotr Does not convert into ROTATE on the gimple
level
