public inbox for gcc-bugs@sourceware.org help / color / mirror / Atom feed
* [Bug rtl-optimization/114243] New: -fsplit-wide-types bloats code by more than 50% @ 2024-03-05 15:56 gjl at gcc dot gnu.org 2024-03-05 20:31 ` [Bug rtl-optimization/114243] [avr] " gjl at gcc dot gnu.org ` (3 more replies) 0 siblings, 4 replies; 5+ messages in thread From: gjl at gcc dot gnu.org @ 2024-03-05 15:56 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114243 Bug ID: 114243 Summary: -fsplit-wide-types bloats code by more than 50% Product: gcc Version: 14.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: rtl-optimization Assignee: unassigned at gcc dot gnu.org Reporter: gjl at gcc dot gnu.org Target Milestone: --- Created attachment 57616 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=57616&action=edit pi-sigma.c: C99 test case Compile the attached test case with: $ avr-gcc pi-sigma.c -c -Os -mmcu=atmega8 -fstack-usage && avr-size pi-sigma.o Then the code sizes are for respective versions of the compiler: avr-gcc-v8: 624 avr-gcc-v14: 1008 which is an increase of code size of more than 60% ! The stack usage also increases by a lot. According to pi-sigma.su: avr-gcc-v8: ----------- pi-sigma.c:80:7:sigma 30 static pi-sigma.c:86:7:pi_n 14 static avr-gcc-v14: ------------ pi-sigma.c:80:7:sigma 86 static pi-sigma.c:86:7:pi_n 36 static That is for the 1st function the stack use almost triples! With -fno-split-wide-types the performace of v14 code is similar to v8. Target: avr Configured with: ../../source/gcc-master/configure --target=avr --disable-nls --with-dwarf2 --with-gnu-as --with-gnu-ld --disable-shared --enable-languages=c,c++ Thread model: single Supported LTO compression algorithms: zlib gcc version 14.0.1 20240303 (experimental) (GCC) ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug rtl-optimization/114243] [avr] -fsplit-wide-types bloats code by more than 50% 2024-03-05 15:56 [Bug rtl-optimization/114243] New: -fsplit-wide-types bloats code by more than 50% gjl at gcc dot gnu.org @ 2024-03-05 20:31 ` gjl at gcc dot gnu.org 2024-03-05 20:40 ` pinskia at gcc dot gnu.org ` (2 subsequent siblings) 3 siblings, 0 replies; 5+ messages in thread From: gjl at gcc dot gnu.org @ 2024-03-05 20:31 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114243 --- Comment #1 from Georg-Johann Lay <gjl at gcc dot gnu.org> --- May be related to PR110093. As Vladimir noted in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110093#c5 the problem is that data flow analysis cannot cope with the subregs generated from lower-subregs, and register alloc chokes at it. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug rtl-optimization/114243] [avr] -fsplit-wide-types bloats code by more than 50% 2024-03-05 15:56 [Bug rtl-optimization/114243] New: -fsplit-wide-types bloats code by more than 50% gjl at gcc dot gnu.org 2024-03-05 20:31 ` [Bug rtl-optimization/114243] [avr] " gjl at gcc dot gnu.org @ 2024-03-05 20:40 ` pinskia at gcc dot gnu.org 2024-06-21 13:17 ` [Bug rtl-optimization/114243] [13/14/15 Regression][avr] " gjl at gcc dot gnu.org 2024-06-21 19:55 ` gjl at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: pinskia at gcc dot gnu.org @ 2024-03-05 20:40 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114243 --- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Subreg improvements to ra is planned for gcc 15 as the riscv folks are running into it for vector modes in some cases. Maybe that will improves the situation here. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug rtl-optimization/114243] [13/14/15 Regression][avr] -fsplit-wide-types bloats code by more than 50% 2024-03-05 15:56 [Bug rtl-optimization/114243] New: -fsplit-wide-types bloats code by more than 50% gjl at gcc dot gnu.org 2024-03-05 20:31 ` [Bug rtl-optimization/114243] [avr] " gjl at gcc dot gnu.org 2024-03-05 20:40 ` pinskia at gcc dot gnu.org @ 2024-06-21 13:17 ` gjl at gcc dot gnu.org 2024-06-21 19:55 ` gjl at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: gjl at gcc dot gnu.org @ 2024-06-21 13:17 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114243 Georg-Johann Lay <gjl at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Ever confirmed|0 |1 Status|UNCONFIRMED |NEW Last reconfirmed| |2024-06-21 --- Comment #3 from Georg-Johann Lay <gjl at gcc dot gnu.org> --- Still present in master. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug rtl-optimization/114243] [13/14/15 Regression][avr] -fsplit-wide-types bloats code by more than 50% 2024-03-05 15:56 [Bug rtl-optimization/114243] New: -fsplit-wide-types bloats code by more than 50% gjl at gcc dot gnu.org ` (2 preceding siblings ...) 2024-06-21 13:17 ` [Bug rtl-optimization/114243] [13/14/15 Regression][avr] " gjl at gcc dot gnu.org @ 2024-06-21 19:55 ` gjl at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: gjl at gcc dot gnu.org @ 2024-06-21 19:55 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114243 --- Comment #4 from Georg-Johann Lay <gjl at gcc dot gnu.org> --- Created attachment 58483 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=58483&action=edit sfmode.c: C test case This is a test case with simpler functions like float add2 (float a, float b) { return a + b; } v8 compiles this with -Os -dp to: add2: rcall __addsf3 ; 9 [c=24 l=1] call_value_insn/1 ret ; 21 [c=0 l=1] return but the current compiler does: add2: push r4 ; 76 [c=4 l=1] pushqi1/0 push r5 ; 77 [c=4 l=1] pushqi1/0 push r6 ; 78 [c=4 l=1] pushqi1/0 push r7 ; 79 [c=4 l=1] pushqi1/0 push r8 ; 80 [c=4 l=1] pushqi1/0 push r9 ; 81 [c=4 l=1] pushqi1/0 push r10 ; 82 [c=4 l=1] pushqi1/0 push r11 ; 83 [c=4 l=1] pushqi1/0 push r12 ; 84 [c=4 l=1] pushqi1/0 push r13 ; 85 [c=4 l=1] pushqi1/0 push r14 ; 86 [c=4 l=1] pushqi1/0 push r15 ; 87 [c=4 l=1] pushqi1/0 /* prologue: function */ /* frame size = 0 */ /* stack size = 12 */ .L__stack_usage = 12 mov r4,r18 ; 61 [c=4 l=1] movqi_insn/0 mov r5,r19 ; 62 [c=4 l=1] movqi_insn/0 mov r6,r20 ; 63 [c=4 l=1] movqi_insn/0 mov r7,r21 ; 64 [c=4 l=1] movqi_insn/0 mov r21,r7 ; 65 [c=4 l=4] *movsf/0 mov r20,r6 mov r19,r5 mov r18,r4 mov r8,r22 ; 66 [c=4 l=1] movqi_insn/0 mov r9,r23 ; 67 [c=4 l=1] movqi_insn/0 mov r10,r24 ; 68 [c=4 l=1] movqi_insn/0 mov r11,r25 ; 69 [c=4 l=1] movqi_insn/0 mov r25,r11 ; 70 [c=4 l=4] *movsf/0 mov r24,r10 mov r23,r9 mov r22,r8 rcall __addsf3 ; 9 [c=24 l=1] call_value_insn/1 mov r12,r22 ; 71 [c=4 l=1] movqi_insn/0 mov r13,r23 ; 72 [c=4 l=1] movqi_insn/0 mov r14,r24 ; 73 [c=4 l=1] movqi_insn/0 mov r15,r25 ; 74 [c=4 l=1] movqi_insn/0 mov r25,r15 ; 75 [c=4 l=4] *movsf/0 mov r24,r14 mov r23,r13 mov r22,r12 /* epilogue start */ pop r15 ; 90 [c=4 l=1] popqi pop r14 ; 91 [c=4 l=1] popqi pop r13 ; 92 [c=4 l=1] popqi pop r12 ; 93 [c=4 l=1] popqi pop r11 ; 94 [c=4 l=1] popqi pop r10 ; 95 [c=4 l=1] popqi pop r9 ; 96 [c=4 l=1] popqi pop r8 ; 97 [c=4 l=1] popqi pop r7 ; 98 [c=4 l=1] popqi pop r6 ; 99 [c=4 l=1] popqi pop r5 ; 100 [c=4 l=1] popqi pop r4 ; 101 [c=4 l=1] popqi ret ; 102 [c=0 l=1] return_from_epilogue ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2024-06-21 19:55 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2024-03-05 15:56 [Bug rtl-optimization/114243] New: -fsplit-wide-types bloats code by more than 50% gjl at gcc dot gnu.org 2024-03-05 20:31 ` [Bug rtl-optimization/114243] [avr] " gjl at gcc dot gnu.org 2024-03-05 20:40 ` pinskia at gcc dot gnu.org 2024-06-21 13:17 ` [Bug rtl-optimization/114243] [13/14/15 Regression][avr] " gjl at gcc dot gnu.org 2024-06-21 19:55 ` 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).