https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67954
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |jakub at gcc dot gnu.org,
| |vmakarov at gcc dot gnu.org
--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Sounds like a RA issue to me.
In *.ira we have:
(jump_insn 175 174 176 26 (parallel [
(set (pc)
(if_then_else (lt (plus:SI (reg/v:SI 134 [ runCount ])
(const_int -1 [0xffffffffffffffff]))
(const_int 0 [0]))
(label_ref 105)
(pc)))
(set (reg/v:SI 152 [ runCount ])
(plus:SI (reg/v:SI 134 [ runCount ])
(const_int -1 [0xffffffffffffffff])))
(clobber (scratch:SI))
]) pr67954.i:89 759 {*addsi3_cbranch}
(expr_list:REG_DEAD (reg/v:SI 134 [ runCount ])
(int_list:REG_BR_PROB 900 (nil)))
-> 105)
and then in *.reload we have:
Choosing alt 4 in insn 175: (0) *?m (1) &l (2) 1 (3) lIJ {*addsi3_cbranch}
...
Choosing alt 1 in insn 175: (0) l (1) X (2) l (3) lL {*addsi3_cbranch}
...
Choosing alt 1 in insn 175: (0) l (1) X (2) l (3) lL {*addsi3_cbranch}
...
Choosing alt 1 in insn 175: (0) l (1) X (2) l (3) lL {*addsi3_cbranch}
...
(jump_insn 175 548 176 26 (parallel [
(set (pc)
(if_then_else (lt (plus:SI (reg:SI 3 r3 [374])
(const_int -1 [0xffffffffffffffff]))
(const_int 0 [0]))
(label_ref 105)
(pc)))
(set (reg/v:SI 2 r2 [orig:152 runCount ] [152])
(plus:SI (reg:SI 3 r3 [374])
(const_int -1 [0xffffffffffffffff])))
(clobber (mem/c:SI (reg:SI 2 r2 [437]) [6 %sfp+-32 S4 A32]))
]) pr67954.i:89 759 {*addsi3_cbranch}
(int_list:REG_BR_PROB 900 (nil))
-> 105)
The pattern has
(clobber (match_scratch:SI 1 "=X,X,l,l,&l,&l"))]
If LRA really chooses the alt 1, then the match_scratch has =X constraint, but
I would expect that it would not leave in complete garbage like the memory
dereference that doesn't pass scratch_operand. Vlad?
Note I could only reproduce this on the 5 branch.
