gnu /
gcc /
4dd2885905afde80da0498f381b0818b05bc9844 LoongArch: Fix wrong code from bstrpick split
After late-combine is added, split1 can see an input like
(insn 56 55 169 5
(set (reg/v:DI 87 [ n ])
(ior:DI (and:DI (reg/v:DI 87 [ n ])
(const_int 281474976710655 [0xffffffffffff]))
(and:DI (reg:DI 131 [ _45 ])
(const_int -281474976710656 [0xffff000000000000]))))
"pr121906.c":22:8 108 {*bstrins_di_for_ior_mask}
(nil))
And the splitter ends up emitting
(insn 184 55 185 5
(set (reg/v:DI 87 [ n ])
(reg:DI 131 [ _45 ]))
"pr121906.c":22:8 -1
(nil))
(insn 185 184 169 5
(set (zero_extract:DI (reg/v:DI 87 [ n ])
(const_int 48 [0x30])
(const_int 0 [0]))
(reg/v:DI 87 [ n ]))
"pr121906.c":22:8 -1
(nil))
which obviously lost everything in r87, instead of retaining its lower
bits as we expect. It's because the splitter didn't anticipate the
output register may be one of the input registers.
PR target/121906
gcc/
* config/loongarch/loongarch.md (*bstrins_<mode>_for_ior_mask):
Always create a new pseudo for the input register of the bstrins
instruction.
gcc/testsuite/
* gcc.target/loongarch/pr121906.c: New test.
(cherry picked from commit 290851e63a5b99c99eb196f2823ea3051c0f0214)
2 files changed
