public inbox for gcc-bugs@sourceware.org help / color / mirror / Atom feed
* [Bug target/56442] New: Could not identify that register is clobbered already @ 2013-02-25 8:42 pitchumani.s at atmel dot com 2013-02-25 8:43 ` [Bug target/56442] " pitchumani.s at atmel dot com ` (4 more replies) 0 siblings, 5 replies; 6+ messages in thread From: pitchumani.s at atmel dot com @ 2013-02-25 8:42 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56442 Bug #: 56442 Summary: Could not identify that register is clobbered already Classification: Unclassified Product: gcc Version: 4.7.2 Status: UNCONFIRMED Severity: major Priority: P3 Component: target AssignedTo: unassigned@gcc.gnu.org ReportedBy: pitchumani.s@atmel.com Wrong code is generated for avr target when gcc-4.7.2 is used. Test case: dejagnu test gcc.dg/var-expand2.c command line options: -O2 -funroll-loops -ffast-math -mmcu=atxmega128b1 (snip of assembly) ldi r24,lo8(array+4) ldi r25,hi8(array+4) sub r14,r24 sbc r15,r25 lsr r15 ror r14 lsr r15 ror r14 ldi r25,3 ;; r25 is overwritten and r14,r25 clr r15 lds r18,array lds r19,array+1 lds r20,array+2 lds r21,array+3 movw r28,r24 ;; register pair r24/r25 is used (snip of assembly) conversation on mailing list: http://gcc.gnu.org/ml/gcc/2013-02/msg00264.html ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug target/56442] Could not identify that register is clobbered already 2013-02-25 8:42 [Bug target/56442] New: Could not identify that register is clobbered already pitchumani.s at atmel dot com @ 2013-02-25 8:43 ` pitchumani.s at atmel dot com 2013-02-25 10:56 ` [Bug other/56442] " gjl at gcc dot gnu.org ` (3 subsequent siblings) 4 siblings, 0 replies; 6+ messages in thread From: pitchumani.s at atmel dot com @ 2013-02-25 8:43 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56442 Pitchumani <pitchumani.s at atmel dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- Target| |a --- Comment #1 from Pitchumani <pitchumani.s at atmel dot com> 2013-02-25 08:43:22 UTC --- (In reply to comment #0) > Wrong code is generated for avr target when gcc-4.7.2 is used. > > Test case: dejagnu test gcc.dg/var-expand2.c > command line options: -O2 -funroll-loops -ffast-math -mmcu=atxmega128b1 -mmcu=atxmega128a1 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug other/56442] Could not identify that register is clobbered already 2013-02-25 8:42 [Bug target/56442] New: Could not identify that register is clobbered already pitchumani.s at atmel dot com 2013-02-25 8:43 ` [Bug target/56442] " pitchumani.s at atmel dot com @ 2013-02-25 10:56 ` gjl at gcc dot gnu.org 2013-06-06 13:26 ` gjl at gcc dot gnu.org ` (2 subsequent siblings) 4 siblings, 0 replies; 6+ messages in thread From: gjl at gcc dot gnu.org @ 2013-02-25 10:56 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56442 Georg-Johann Lay <gjl at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Keywords| |wrong-code Status|UNCONFIRMED |NEW Last reconfirmed| |2013-02-25 CC| |gjl at gcc dot gnu.org Component|target |other Ever Confirmed|0 |1 Severity|major |normal --- Comment #2 from Georg-Johann Lay <gjl at gcc dot gnu.org> 2013-02-25 10:56:02 UTC --- Enabling others to understand this... In .reload dump, we have correct code: (insn 418 417 113 3 (set (reg:HI 24 r24) (const:HI (plus:HI (symbol_ref:HI ("array") [flags 0x2] <var_decl 0x1e405a0 array>) (const_int 4 [0x4])))) 32 {*movhi} (nil)) (insn 113 418 114 3 (set (reg:HI 14 r14 [94]) (minus:HI (reg:HI 14 r14 [94]) (reg:HI 24 r24))) 65 {subhi3} (nil)) (insn 114 113 115 3 (set (reg:HI 14 r14 [94]) (lshiftrt:HI (reg:HI 14 r14 [94]) (const_int 2 [0x2]))) 217 {lshrhi3} (nil)) (insn 115 114 118 3 (parallel [ (set (reg:HI 14 r14 [94]) (and:HI (reg:HI 14 r14 [94]) (const_int 3 [0x3]))) (clobber (reg:QI 25 r25)) ]) 175 {andhi3} (nil)) (insn 118 115 119 3 (set (reg:SF 18 r18 [orig:65 D.1335 ] [65]) (mem:SF (symbol_ref:HI ("array") [flags 0x2] <var_decl 0x1e405a0 array>) [2 MEM[base: D.1358_18, offset: 0B]+0 S4 A8])) foo.c:15 37 {*movsf} (nil)) (insn 119 118 122 3 (set (reg:HI 28 r28 [orig:96 ivtmp.10 ] [96]) (const:HI (plus:HI (symbol_ref:HI ("array") [flags 0x2] <var_decl 0x1e405a0 array>) (const_int 4 [0x4])))) 32 {*movhi} (expr_list:REG_EQUAL (const:HI (plus:HI (symbol_ref:HI ("array") [flags 0x2] <var_decl 0x1e405a0 array>) (const_int 4 [0x4]))) (nil))) This is changed by .postreload to: (insn 119 118 122 3 (set (reg:HI 28 r28 [orig:96 ivtmp.10 ] [96]) (reg:HI 24 r24)) 32 {*movhi} (expr_list:REG_EQUAL (const:HI (plus:HI (symbol_ref:HI ("array") [flags 0x2] <var_decl 0x1e405a0 array>) (const_int 4 [0x4]))) (nil))) This is wrong because reg:HI 24 is (partly) clobbered by insn 115 and thus reg:HI 24 must not be used past insn 115. Component is not target, the target description of andhi3 insn is all right. According to S, the bad transformation happens in: postreload.c:reload_cse_move2add() ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug other/56442] Could not identify that register is clobbered already 2013-02-25 8:42 [Bug target/56442] New: Could not identify that register is clobbered already pitchumani.s at atmel dot com 2013-02-25 8:43 ` [Bug target/56442] " pitchumani.s at atmel dot com 2013-02-25 10:56 ` [Bug other/56442] " gjl at gcc dot gnu.org @ 2013-06-06 13:26 ` gjl at gcc dot gnu.org 2014-06-12 13:53 ` [Bug other/56442] postreload uses content of clobbered register rguenth at gcc dot gnu.org 2024-01-18 9:55 ` [Bug rtl-optimization/56442] " gjl at gcc dot gnu.org 4 siblings, 0 replies; 6+ messages in thread From: gjl at gcc dot gnu.org @ 2013-06-06 13:26 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56442 Georg-Johann Lay <gjl at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |eric.weddington at atmel dot com Target Milestone|--- |4.7.4 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug other/56442] postreload uses content of clobbered register 2013-02-25 8:42 [Bug target/56442] New: Could not identify that register is clobbered already pitchumani.s at atmel dot com ` (2 preceding siblings ...) 2013-06-06 13:26 ` gjl at gcc dot gnu.org @ 2014-06-12 13:53 ` rguenth at gcc dot gnu.org 2024-01-18 9:55 ` [Bug rtl-optimization/56442] " gjl at gcc dot gnu.org 4 siblings, 0 replies; 6+ messages in thread From: rguenth at gcc dot gnu.org @ 2014-06-12 13:53 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56442 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Target Milestone|4.7.4 |--- --- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> --- Unsetting target milestone of open non-regression bug from version of branch being closed. ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug rtl-optimization/56442] postreload uses content of clobbered register 2013-02-25 8:42 [Bug target/56442] New: Could not identify that register is clobbered already pitchumani.s at atmel dot com ` (3 preceding siblings ...) 2014-06-12 13:53 ` [Bug other/56442] postreload uses content of clobbered register rguenth at gcc dot gnu.org @ 2024-01-18 9:55 ` gjl at gcc dot gnu.org 4 siblings, 0 replies; 6+ messages in thread From: gjl at gcc dot gnu.org @ 2024-01-18 9:55 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56442 --- Comment #4 from Georg-Johann Lay <gjl at gcc dot gnu.org> --- Maybe this is similar to PR101188. ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2024-01-18 9:55 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2013-02-25 8:42 [Bug target/56442] New: Could not identify that register is clobbered already pitchumani.s at atmel dot com 2013-02-25 8:43 ` [Bug target/56442] " pitchumani.s at atmel dot com 2013-02-25 10:56 ` [Bug other/56442] " gjl at gcc dot gnu.org 2013-06-06 13:26 ` gjl at gcc dot gnu.org 2014-06-12 13:53 ` [Bug other/56442] postreload uses content of clobbered register rguenth at gcc dot gnu.org 2024-01-18 9:55 ` [Bug rtl-optimization/56442] " gjl at gcc dot gnu.org
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).