https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108102
--- Comment #11 from Stefan Schulze Frielinghaus <stefansf at linux dot
ibm.com> ---
Please find attached a reduced version of the initial problem. If compiled
with
g++ -O2 -march=arch13 -fno-exceptions (-g)
there is still a difference whether build with debug information or not:
diff <(objdump -d reduced.o-without-debug) <(objdump -d reduced.o-with-debug)
2c2
< reduced.o-without-debug: file format elf64-s390
---
> reduced.o-with-debug: file format elf64-s390
94,97c94,97
< 1b8: e5 48 f0 a8 00 00 mvghi 168(%r15),0
< 1be: e3 50 f0 c8 00 04 lg %r5,200(%r15)
< 1c4: 41 30 f0 a0 la %r3,160(%r15)
< 1c8: e3 50 f0 a0 00 24 stg %r5,160(%r15)
---
> 1b8: e3 50 f0 c8 00 04 lg %r5,200(%r15)
> 1be: e5 48 f0 a8 00 00 mvghi 168(%r15),0
> 1c4: e3 50 f0 a0 00 24 stg %r5,160(%r15)
> 1ca: 41 30 f0 a0 la %r3,160(%r15)
The corresponding insns are:
Without debug information:
mvghi => insn 207
lg => insn 206
la => insn 310
stg => insn 312
With debug information:
lg => insn 427
mvghi => insn 428
stg => insn 533
la => insn 531
In split3 the order of the insns are the same and change in sched2 where we
have:
Without debug information:
;; ======================================================
;; -- basic block 14 from 87 to 355 -- after reload
;; ======================================================
;; 0--> b 0: i 87 %r2=0 :nothing
;; 1--> b 0: i 88 {%r2=call
[`_ZN4Rust4TyTy9ParamType7resolveEv'];clobber %r14;}:nothing
;; 2--> b 0: i 207 [%r15+0xa8]=0 :nothing
;; 3--> b 0: i 206 %r5=[%r15+0xc8] :nothing
;; 4--> b 0: i 310 %r3=%r15+0xa0 :nothing
;; 5--> b 0: i 312 [%r15+0xa0]=%r5 :nothing
;; 6--> b 0: i 311 %r2=%r15+0xc0 :nothing
;; 7--> b 0: i 96 {call
[`_ZNSt6vectorIPN4Rust4TyTy8BaseTypeESaIS3_EE17_M_realloc_insertIN9__gnu_cxx17__normal_iteratorIPS3_S5_EEEEvT_'];clobber
%r14;}:nothing
;; 8--> b 0: i 355 pc=L174 :nothing
;; Ready list (final):
;; total time = 8
;; new head = 87
;; new tail = 355
With debug information:
;; ======================================================
;; -- basic block 14 from 201 to 585 -- after reload
;; ======================================================
;; 0--> b 0: i 201 debug_marker :nothing
;; 0--> b 0: i 202 %r2=0 :nothing
;; 1--> b 0: i 203 {%r2=call
[`_ZN4Rust4TyTy9ParamType7resolveEv'];clobber %r14;}:nothing
;; 1--> b 0: i 204 debug_marker :nothing
;; 1--> b 0: i 205 loc %r15+0xc0 :nothing
;; 1--> b 0: i 206 debug_marker :nothing
;; 1--> b 0: i 207 loc %r15+0xc0 :nothing
;; 1--> b 0: i 208 debug_marker :nothing
;; 1--> b 0: i 210 loc debug_implicit_ptr :nothing
;; 1--> b 0: i 211 loc [%r15+0xc8] :nothing
;; 1--> b 0: i 212 debug_marker :nothing
;; 1--> b 0: i 214 loc clobber :nothing
;; 1--> b 0: i 215 loc clobber :nothing
;; 1--> b 0: i 216 loc clobber :nothing
;; 2--> b 0: i 427 %r5=[%r15+0xc8] :nothing
;; 3--> b 0: i 428 [%r15+0xa8]=0 :nothing
;; 4--> b 0: i 533 [%r15+0xa0]=%r5 :nothing
;; 5--> b 0: i 531 %r3=%r15+0xa0 :nothing
;; 6--> b 0: i 532 %r2=%r15+0xc0 :nothing
;; 7--> b 0: i 222 {call
[`_ZNSt6vectorIPN4Rust4TyTy8BaseTypeESaIS3_EE17_M_realloc_insertIN9__gnu_cxx17__normal_iteratorIPS3_S5_EEEEvT_'];clobber
%r14;}:nothing
;; 7--> b 0: i 223 loc clobber :nothing
;; 8--> b 0: i 585 pc=L373 :nothing
;; Ready list (final):
;; total time = 8
;; new head = 201
;; new tail = 585
