https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118067
Uroš Bizjak <ubizjak at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Component|target |rtl-optimization
CC| |vmakarov at gcc dot gnu.org
Status|UNCONFIRMED |NEW
Ever confirmed|0 |1
Last reconfirmed| |2024-12-19
--- Comment #1 from Uroš Bizjak <ubizjak at gmail dot com> ---
This is the problematic insn in _.c.322r.ira dump:
(insn 9 5 10 2 (parallel [
(set (reg:HI 99 [ _2 ])
(lshiftrt:HI (subreg:HI (reg/v:V32HI 165 [ u ]) 0)
(const_int 1 [0x1])))
(clobber (reg:CC 17 flags))
]) "pr118067.c":10:8 1215 {*lshrhi3_1}
(expr_list:REG_UNUSED (reg:CC 17 flags)
(nil)))
Reload tries to reload input operand with:
(insn 193 5 191 2 (set (reg:SI 338)
(subreg/j:SI (reg/v:V32HI 165 [ u ]) 0)) "pr118067.c":10:8 96
{*movsi_internal}
(nil))
(note 191 193 192 2 NOTE_INSN_DELETED)
(insn 192 191 9 2 (set (subreg/j:SI (reg:HI 337) 0)
(reg:SI 338)) "pr118067.c":10:8 96 {*movsi_internal}
(expr_list:REG_DEAD (reg:SI 338)
(nil)))
(insn 9 192 10 2 (parallel [
(set (reg:HI 99 [ _2 ])
(lshiftrt:HI (reg:HI 337)
(const_int 1 [0x1])))
(clobber (reg:CC 17 flags))
]) "pr118067.c":10:8 1215 {*lshrhi3_1}
(expr_list:REG_DEAD (reg:HI 337)
(expr_list:REG_UNUSED (reg:CC 17 flags)
(nil))))
...
(insn 209 156 158 2 (set (reg:HI 354 [orig:99 _2 ] [99])
(reg:HI 99 [ _2 ])) "pr118067.c":10:8 97 {*movhi_internal}
(expr_list:REG_DEAD (reg:HI 99 [ _2 ])
(nil)))
and chooses alternative 1 using mask register reload r337:
Choosing alt 1 in insn 9: (0) ?k (1) k (2) Ww {*lshrhi3_1}
Creating newreg=337, assigning class ALL_MASK_REGS to r337
and:
Creating newreg=338, assigning class NO_REGS to secondary r338
deleting insn with uid = 191.
with:
Choosing alt 11 in insn 193: (0) m (1) ?v {*movsi_internal}
Choosing alt 15 in insn 192: (0) *k (1) *kBk {*movsi_internal}
Choosing alt 6 in insn 209: (0) r (1) *k {*movhi_internal}
There are plenty of mask registers available, so there is no reason for spill
failure.
Confirmed as RA problem, CC added.
