[Bug rtl-optimization/67954] [5 / 6 Regression] internal compiler error: in patch_jump_insn, at cfgrtl.c:1303

["jakub at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

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.