On Wed, Dec 21, 2016 at 01:58:18PM +0100, Georg-Johann Lay wrote:
> On 12.12.2016 17:54, Segher Boessenkool wrote:
> >On Mon, Dec 12, 2016 at 05:46:02PM +0100, Dominik Vogt wrote:
> >>Patch with these changes and a fix because of not handling
> >>VOIDmode attached. Bootstrapped and regression tested on s390 and
> >>s390x.
> >
> >Okay for trunk.
> >
> >When did you see VOIDmode, btw? It wasn't on a const_int I hope?
> >
> >
> >Segher
> >
> >
> >> * combine.c (change_zero_ext): Handle mode expanding zero_extracts.
>
> This was committes as r243578 and triggered (amongst other similar
> test suite ICE failures):
>
> $ avr-gcc
> /gnu/gcc.gnu.org/trunk/gcc/testsuite/gcc.c-torture/compile/pr26833.c
> -S -O1 -mmcu=avr4 -S -v
>
> /gnu/gcc.gnu.org/trunk/gcc/testsuite/gcc.c-torture/compile/pr26833.c:
> In function 'yasm_lc3b__parse_insn':
> /gnu/gcc.gnu.org/trunk/gcc/testsuite/gcc.c-torture/compile/pr26833.c:19:1:
> error: insn does not satisfy its constraints:
> }
> ^
> (jump_insn 58 98 59 9 (set (pc)
> (if_then_else (eq (and:HI (reg:HI 31 r31)
> (const_int 1 [0x1]))
> (const_int 0 [0]))
> (label_ref 70)
> (pc)))
> "/gnu/gcc.gnu.org/trunk/gcc/testsuite/gcc.c-torture/compile/pr26833.c":11
> 415 {*sbrx_and_branchhi}
> (int_list:REG_BR_PROB 375 (nil))
> -> 70)
Does that mean that, on avr, this is valid:
(zero_extract:HI (reg:QI 31) ...)
but this is not:
(subreg:HI (reg:QI 31))
?
> /gnu/gcc.gnu.org/trunk/gcc/testsuite/gcc.c-torture/compile/pr26833.c:19:1:
> internal compiler error: in extract_constrain_insn, at recog.c:2213
> 0x9836a3 _fatal_insn(char const*, rtx_def const*, char const*, int,
> char const*)
> ../../../gcc.gnu.org/trunk/gcc/rtl-error.c:108
> 0x9836cf _fatal_insn_not_found(rtx_def const*, char const*, int,
> char const*)
> ../../../gcc.gnu.org/trunk/gcc/rtl-error.c:119
> 0x95abdd extract_constrain_insn(rtx_insn*)
> ../../../gcc.gnu.org/trunk/gcc/recog.c:2213
> 0x939105 reload_cse_simplify_operands
> ../../../gcc.gnu.org/trunk/gcc/postreload.c:391
> 0x939ce5 reload_cse_simplify
> ../../../gcc.gnu.org/trunk/gcc/postreload.c:179
> 0x939ce5 reload_cse_regs_1
> ../../../gcc.gnu.org/trunk/gcc/postreload.c:218
> 0x93b96b reload_cse_regs
> ../../../gcc.gnu.org/trunk/gcc/postreload.c:64
> 0x93b96b execute
> ../../../gcc.gnu.org/trunk/gcc/postreload.c:2342
> Please submit a full bug report,
> with preprocessed source if appropriate.
> Please include the complete backtrace with any bug report.
> See <http://gcc.gnu.org/bugs.html> for instructions.
>
>
> Target: avr
> Configured with: ../../gcc.gnu.org/trunk/configure --target=avr
> --prefix=/local/gnu/install/gcc-7 --disable-shared --disable-nls
> --with-dwarf2 --enable-target-optspace=yes --with-gnu-as
> --with-gnu-ld --enable-checking=release --enable-languages=c,c++
>
>
> Combine comes up with the following insn:
> (jump_insn 58 57 59 7 (set (pc)
> (if_then_else (eq (and:HI (subreg:HI (mem:QI (reg/v/f:HI 75
> [ operands ]) [1 *operands_17(D)+0 S1 A8]) 0)
> (const_int 1 [0x1]))
> (const_int 0 [0]))
> (label_ref 70)
> (pc)))
> "/home/georg/gnu/gcc.gnu.org/trunk/gcc/testsuite/gcc.c-torture/compile/pr26833.c":11
> 415 {*sbrx_and_branchhi}
> (int_list:REG_BR_PROB 375 (nil))
> -> 70)
>
> which cannot be correct because avr.md::*sbrx_and_branchhi reads:
>
> (define_insn "*sbrx_and_branch<mode>"
> [(set (pc)
> (if_then_else
> (match_operator 0 "eqne_operator"
> [(and:QISI
> (match_operand:QISI 1 "register_operand" "r")
> (match_operand:QISI 2 "single_one_operand" "n"))
> (const_int 0)])
> (label_ref (match_operand 3 "" ""))
> (pc)))]
> "" { ... } ...)
>
> Hence we have a memory operand (subreg of mem)) where only a
> register is allowed. Reg alloc then reloads the mem:QI into R31,
> but R31 is the
> last hard reg, i.e. R31 cannot hold HImode.
>
> Johann
>
>
>
Ciao
Dominik ^_^ ^_^
--
Dominik Vogt
IBM Germany
