On Tue, Apr 19, 2022 at 04:05:06PM +0800, HAO CHEN GUI wrote:
> I tested the test case on Linux and AIX with both big and little endian.
> The test case requires lp64 target, so it won't be tested on 32-bit targets.
>
> On big endian (both AIX and Linux), it should match
> (compare:CC (and:SI (subreg:SI (reg:DI 207) 4)
>
> On little endian (both AIX and Linux), it should match
> (compare:CC (and:SI (subreg:SI (reg:DI 207) 0)
>
> So, the pattern in my patch should work fine.
>
> /* { dg-final { scan-rtl-dump-times {\(compare:CC \(and:SI \(subreg:SI
> \(reg:DI} 1 "combine" } } */
On powerpc64-linux:
FAIL: gcc.target/powerpc/pr56605.c scan-rtl-dump-times combine "\\(compare:CC
\\((?:and|zero_extend):(?:[SD]I) \\((?:sub)?reg:[SD]I" 1
It matches twice instead of once, namely:
(insn 19 18 20 2 (parallel [
(set (reg:CC 208)
(compare:CC (and:SI (subreg:SI (reg:DI 207) 4)
(const_int 3 [0x3]))
(const_int 0 [0])))
(set (reg:SI 129 [ prolog_loop_niters.5 ])
(and:SI (subreg:SI (reg:DI 207) 4)
(const_int 3 [0x3])))
]) 208 {*andsi3_imm_mask_dot2}
(nil))
(insn 81 80 82 11 (parallel [
(set (reg:CC 232)
(compare:CC (and:DI (subreg:DI (reg:SI 136 [ niters.6 ]) 0)
(const_int 7 [0x7]))
(const_int 0 [0])))
(clobber (scratch:DI))
]) 207 {*anddi3_imm_mask_dot}
(expr_list:REG_DEAD (reg:SI 136 [ niters.6 ])
(nil)))
The paradoxical subreg in the latter wasn't expected :-)
Segher
