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* [Bug ada/64180] New: PowerPC carry bit improvements @ 2014-12-04 2:23 segher at gcc dot gnu.org 2014-12-04 18:38 ` [Bug target/64180] " dje at gcc dot gnu.org ` (9 more replies) 0 siblings, 10 replies; 11+ messages in thread From: segher at gcc dot gnu.org @ 2014-12-04 2:23 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64180 Bug ID: 64180 Summary: PowerPC carry bit improvements Product: gcc Version: unknown Status: UNCONFIRMED Severity: normal Priority: P3 Component: ada Assignee: segher at gcc dot gnu.org Reporter: segher at gcc dot gnu.org Target: powerpc*-*-* In current mainline, every RTL instruction that uses XER[CA] (the carry bit) will have to set it in the same instruction, because other instructions clobber it at will. Those RTL insns then are output as multiple machine insns. This is bad for multiple reasons: 1) It leads to code explosion: we have patterns like and_neg_geu. None of those are necessary if we can just express the machine insns as separate RTL insns directly. 2) There are so many possible combinations that some are missed, or deemed not worth the effort (and cost) to implement as RTL insns. This is especially true of the multi-precision add/sub patterns. As a consequence we get not very well optimised code. 3) The resulting insns are not scheduled well. So, let's improve this. THE PLAN ======== First, we need to let GCC know about the CA bit. This is done. GCC thinks the register is SImode or DImode, which is a) fine, because it will never allocate anything to it itself, and we write only 0 or 1 to it; and b) handy, because we have to do arithmetic with it in those modes all the time. Secondly, we need to change all the patterns that clobber CA so that either: a) they don't clobber it anymore; or b) the clobber is explicit. This is partly done. Remaining are two classes of insns: 1) those that should be split into separate insns; and 2) those that slightly regress code quality if changed (mostly those use "addic" so they can use GPR0 as well as all other GPRs). The insns in 1) are the multi-precision add/sub/neg, and all the various eq/ne/ltu/gtu/leu/geu things. These all have to be done at the same time, using... Thirdly, we need to add patterns for the actual machine insns. For things like "addic" we need multiple patterns, one each per kind of immediate op (pos/neg/0/-1), since canonical RTL for those is different. We also should make all asm() clobber CA implicitly, because quite a lot of code in the field clobbers it without telling the compiler. Finally, as a further improvement, we should put some extra attributes on the "C" and "E" insns so that the scheduling descriptions can be made more accurate; and those scheduling descriptions then should be updated. ^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug target/64180] PowerPC carry bit improvements 2014-12-04 2:23 [Bug ada/64180] New: PowerPC carry bit improvements segher at gcc dot gnu.org @ 2014-12-04 18:38 ` dje at gcc dot gnu.org 2014-12-10 18:29 ` segher at gcc dot gnu.org ` (8 subsequent siblings) 9 siblings, 0 replies; 11+ messages in thread From: dje at gcc dot gnu.org @ 2014-12-04 18:38 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64180 David Edelsohn <dje at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Last reconfirmed| |2014-12-04 CC| |dje at gcc dot gnu.org Ever confirmed|0 |1 Severity|normal |enhancement --- Comment #1 from David Edelsohn <dje at gcc dot gnu.org> --- Confirmed. Very nice enhancement. ^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug target/64180] PowerPC carry bit improvements 2014-12-04 2:23 [Bug ada/64180] New: PowerPC carry bit improvements segher at gcc dot gnu.org 2014-12-04 18:38 ` [Bug target/64180] " dje at gcc dot gnu.org @ 2014-12-10 18:29 ` segher at gcc dot gnu.org 2014-12-10 18:31 ` segher at gcc dot gnu.org ` (7 subsequent siblings) 9 siblings, 0 replies; 11+ messages in thread From: segher at gcc dot gnu.org @ 2014-12-10 18:29 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64180 --- Comment #2 from Segher Boessenkool <segher at gcc dot gnu.org> --- Author: segher Date: Wed Dec 10 18:28:57 2014 New Revision: 218589 URL: https://gcc.gnu.org/viewcvs?rev=218589&root=gcc&view=rev Log: PR target/64180 * config/rs6000/rs6000.c (TARGET_MD_ASM_CLOBBERS): Define. (rs6000_md_asm_clobbers): New function. Modified: trunk/gcc/ChangeLog trunk/gcc/config/rs6000/rs6000.c ^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug target/64180] PowerPC carry bit improvements 2014-12-04 2:23 [Bug ada/64180] New: PowerPC carry bit improvements segher at gcc dot gnu.org 2014-12-04 18:38 ` [Bug target/64180] " dje at gcc dot gnu.org 2014-12-10 18:29 ` segher at gcc dot gnu.org @ 2014-12-10 18:31 ` segher at gcc dot gnu.org 2014-12-10 18:31 ` segher at gcc dot gnu.org ` (6 subsequent siblings) 9 siblings, 0 replies; 11+ messages in thread From: segher at gcc dot gnu.org @ 2014-12-10 18:31 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64180 --- Comment #4 from Segher Boessenkool <segher at gcc dot gnu.org> --- Author: segher Date: Wed Dec 10 18:31:15 2014 New Revision: 218591 URL: https://gcc.gnu.org/viewcvs?rev=218591&root=gcc&view=rev Log: PR target/64180 * config/rs6000/rs6000.md (*ctr<mode>_internal1, *ctr<mode>_internal2, *ctr<mode>_internal5, *ctr<mode>_internal6): Change "r" alternatives to "b". Increase length. (splitters for these): Split to cmp+addi instead of addic. Modified: trunk/gcc/ChangeLog trunk/gcc/config/rs6000/rs6000.md ^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug target/64180] PowerPC carry bit improvements 2014-12-04 2:23 [Bug ada/64180] New: PowerPC carry bit improvements segher at gcc dot gnu.org ` (2 preceding siblings ...) 2014-12-10 18:31 ` segher at gcc dot gnu.org @ 2014-12-10 18:31 ` segher at gcc dot gnu.org 2014-12-10 18:32 ` segher at gcc dot gnu.org ` (5 subsequent siblings) 9 siblings, 0 replies; 11+ messages in thread From: segher at gcc dot gnu.org @ 2014-12-10 18:31 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64180 --- Comment #3 from Segher Boessenkool <segher at gcc dot gnu.org> --- Author: segher Date: Wed Dec 10 18:30:07 2014 New Revision: 218590 URL: https://gcc.gnu.org/viewcvs?rev=218590&root=gcc&view=rev Log: PR target/64180 * config/rs6000/darwin.md (macho_low_si): Remove "r" alternative. (macho_low_di): Ditto. * config/rs6000/rs6000.md (*largetoc_low): Ditto. (tocref<mode>): Ditto. (elf_low): Ditto. * config/rs6000/spe.md (mov_si<mode>_e500_subreg0_elf_low_be): Ditto. (mov_si<mode>_e500_subreg0_elf_low_le): Ditto. (mov_si<mode>_e500_subreg4_elf_low_be): Ditto. Reformat condition. (mov_si<mode>_e500_subreg4_elf_low_le): Ditto. Modified: trunk/gcc/ChangeLog trunk/gcc/config/rs6000/darwin.md trunk/gcc/config/rs6000/rs6000.md trunk/gcc/config/rs6000/spe.md ^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug target/64180] PowerPC carry bit improvements 2014-12-04 2:23 [Bug ada/64180] New: PowerPC carry bit improvements segher at gcc dot gnu.org ` (3 preceding siblings ...) 2014-12-10 18:31 ` segher at gcc dot gnu.org @ 2014-12-10 18:32 ` segher at gcc dot gnu.org 2014-12-10 18:34 ` segher at gcc dot gnu.org ` (4 subsequent siblings) 9 siblings, 0 replies; 11+ messages in thread From: segher at gcc dot gnu.org @ 2014-12-10 18:32 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64180 --- Comment #5 from Segher Boessenkool <segher at gcc dot gnu.org> --- Author: segher Date: Wed Dec 10 18:32:15 2014 New Revision: 218592 URL: https://gcc.gnu.org/viewcvs?rev=218592&root=gcc&view=rev Log: PR target/64180 * config/rs6000/rs6000.md (*add<mode>3_internal1): Remove addic alternative. Modified: trunk/gcc/ChangeLog trunk/gcc/config/rs6000/rs6000.md ^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug target/64180] PowerPC carry bit improvements 2014-12-04 2:23 [Bug ada/64180] New: PowerPC carry bit improvements segher at gcc dot gnu.org ` (4 preceding siblings ...) 2014-12-10 18:32 ` segher at gcc dot gnu.org @ 2014-12-10 18:34 ` segher at gcc dot gnu.org 2014-12-10 18:36 ` segher at gcc dot gnu.org ` (3 subsequent siblings) 9 siblings, 0 replies; 11+ messages in thread From: segher at gcc dot gnu.org @ 2014-12-10 18:34 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64180 --- Comment #6 from Segher Boessenkool <segher at gcc dot gnu.org> --- Author: segher Date: Wed Dec 10 18:33:26 2014 New Revision: 218593 URL: https://gcc.gnu.org/viewcvs?rev=218593&root=gcc&view=rev Log: PR target/64180 * config/rs6000/rs6000.md (*add<mode>3_internal1): Rename to "*add<mode>3". (*add<mode>3_internal2, *add<mode>3_internal3, and (their splitters): Delete. (*add<mode>3_dot, *add<mode>3_dot2): New. (*add<mode>3_imm_dot, *add<mode>3_imm_dot2): New. Modified: trunk/gcc/ChangeLog trunk/gcc/config/rs6000/rs6000.md ^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug target/64180] PowerPC carry bit improvements 2014-12-04 2:23 [Bug ada/64180] New: PowerPC carry bit improvements segher at gcc dot gnu.org ` (5 preceding siblings ...) 2014-12-10 18:34 ` segher at gcc dot gnu.org @ 2014-12-10 18:36 ` segher at gcc dot gnu.org 2014-12-10 18:38 ` segher at gcc dot gnu.org ` (2 subsequent siblings) 9 siblings, 0 replies; 11+ messages in thread From: segher at gcc dot gnu.org @ 2014-12-10 18:36 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64180 --- Comment #7 from Segher Boessenkool <segher at gcc dot gnu.org> --- Author: segher Date: Wed Dec 10 18:36:18 2014 New Revision: 218594 URL: https://gcc.gnu.org/viewcvs?rev=218594&root=gcc&view=rev Log: PR target/64180 * config/rs6000/predicates.md (adde_operand): New. * config/rs6000/rs6000.md (add<mode>3_carry): New. (*add<mode>3_imm_carry_pos): New. (*add<mode>3_imm_carry_0): New. (*add<mode>3_imm_carry_m1): New. (*add<mode>3_imm_carry_neg): New. (add<mode>3_carry_in): New. (*add<mode>3_carry_in_internal): New. (add<mode>3_carry_in_0): New. (add<mode>3_carry_in_m1): New. (subf<mode>3_carry): New. (*subf<mode>3_imm_carry_0): New. (*subf<mode>3_imm_carry_m1): New. (subf<mode>3_carry_in): New. (*subf<mode>3_carry_in_internal): New. (subf<mode>3_carry_in_0): New. (subf<mode>3_carry_in_m1): New. (subf<mode>3_carry_in_xx): New. Modified: trunk/gcc/ChangeLog trunk/gcc/config/rs6000/predicates.md trunk/gcc/config/rs6000/rs6000.md ^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug target/64180] PowerPC carry bit improvements 2014-12-04 2:23 [Bug ada/64180] New: PowerPC carry bit improvements segher at gcc dot gnu.org ` (6 preceding siblings ...) 2014-12-10 18:36 ` segher at gcc dot gnu.org @ 2014-12-10 18:38 ` segher at gcc dot gnu.org 2014-12-12 21:20 ` pthaugen at gcc dot gnu.org 2015-01-02 2:16 ` segher at gcc dot gnu.org 9 siblings, 0 replies; 11+ messages in thread From: segher at gcc dot gnu.org @ 2014-12-10 18:38 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64180 --- Comment #8 from Segher Boessenkool <segher at gcc dot gnu.org> --- Author: segher Date: Wed Dec 10 18:37:58 2014 New Revision: 218595 URL: https://gcc.gnu.org/viewcvs?rev=218595&root=gcc&view=rev Log: PR target/64180 * config/rs6000/predicates.md (unsigned_comparison_operator): New. (signed_comparison_operator): New. * config/rs6000/rs6000-protos.h (rs6000_emit_eqne): Declare. * config/rs6000/rs6000.c (rs6000_emit_eqne): New function. (rs6000_emit_sCOND): Remove ISEL test (move it to the expander). * config/rs6000/rs6000.md (add<mode>3 for SDI): Expand DImode add to addc,adde directly, if !TARGET_POWERPC64. (sub<mode>3 for SDI): Expand DImode sub to subfc,subfe directly, if !TARGET_POWERPC64. (neg<mode>2): Delete expander. (*neg<mode>2): Rename to "neg<mode>2". (addti3, subti3): Delete. (addti3, subti3): New expanders. (*adddi3_noppc64, *subdi3_noppc64, *negdi2_noppc64): Delete. (cstore<mode>4_unsigned): New expander. (cstore<mode>4): Allow GPR as output (not just SI). Rewrite. (cstore<mode>4 for FP): Remove superfluous quotes. (*eq<mode>, *eq<mode>_compare, *plus_eqsi and splitter, *compare_plus_eqsi and splitter, *plus_eqsi_compare and splitter, *neg_eq0<mode>, *neg_eq<mode>, *ne0_<mode>, plus_ne0_<mode>, compare_plus_ne0_<mode> and splitter, *compare_plus_ne0_<mode>_1 and splitter, *plus_ne0_<mode>_compare and splitter, *leu<mode>, *leu<mode>_compare and splitter, *plus_leu<mode>, *neg_leu<mode>, *and_neg_leu<mode>, *ltu<mode>, *ltu<mode>_compare, *plus_ltu<mode>, *plus_ltu<mode>_1, *plus_ltu<mode>compare, *neg_ltu<mode>, *geu<mode>, *geu<mode>_compare and splitter, *plus_geu<mode>, *neg_geu<mode>, *and_neg_geu<mode>, *plus_gt0<mode>, *gtu<mode>, *gtu<mode>_compare, *plus_gtu<mode>, *plus_gtu<mode>_1, *plus_gtu<mode>_compare, *neg_gtu<mode>, 12 anonymous insns, and 12 anonymous splitters): Delete. (eq<mode>3, ne<mode>3): New. (*neg_eq_<mode>, *neg_ne_<mode>): New. (*plus_eq_<mode>, *plus_ne_<mode>): New. (*minus_eq_<mode>, *minus_ne_<mode>): New. Modified: trunk/gcc/ChangeLog trunk/gcc/config/rs6000/predicates.md trunk/gcc/config/rs6000/rs6000-protos.h trunk/gcc/config/rs6000/rs6000.c trunk/gcc/config/rs6000/rs6000.md ^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug target/64180] PowerPC carry bit improvements 2014-12-04 2:23 [Bug ada/64180] New: PowerPC carry bit improvements segher at gcc dot gnu.org ` (7 preceding siblings ...) 2014-12-10 18:38 ` segher at gcc dot gnu.org @ 2014-12-12 21:20 ` pthaugen at gcc dot gnu.org 2015-01-02 2:16 ` segher at gcc dot gnu.org 9 siblings, 0 replies; 11+ messages in thread From: pthaugen at gcc dot gnu.org @ 2014-12-12 21:20 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64180 Pat Haugen <pthaugen at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |pthaugen at gcc dot gnu.org --- Comment #9 from Pat Haugen <pthaugen at gcc dot gnu.org> --- (In reply to Segher Boessenkool from comment #8) > Author: segher > Date: Wed Dec 10 18:37:58 2014 > New Revision: 218595 > This revision causes CPU2000 benchmark 186.crafty to loop when compiled with -m32. ^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug target/64180] PowerPC carry bit improvements 2014-12-04 2:23 [Bug ada/64180] New: PowerPC carry bit improvements segher at gcc dot gnu.org ` (8 preceding siblings ...) 2014-12-12 21:20 ` pthaugen at gcc dot gnu.org @ 2015-01-02 2:16 ` segher at gcc dot gnu.org 9 siblings, 0 replies; 11+ messages in thread From: segher at gcc dot gnu.org @ 2015-01-02 2:16 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64180 Segher Boessenkool <segher at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution|--- |FIXED --- Comment #10 from Segher Boessenkool <segher at gcc dot gnu.org> --- All done. ^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2015-01-02 2:16 UTC | newest] Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2014-12-04 2:23 [Bug ada/64180] New: PowerPC carry bit improvements segher at gcc dot gnu.org 2014-12-04 18:38 ` [Bug target/64180] " dje at gcc dot gnu.org 2014-12-10 18:29 ` segher at gcc dot gnu.org 2014-12-10 18:31 ` segher at gcc dot gnu.org 2014-12-10 18:31 ` segher at gcc dot gnu.org 2014-12-10 18:32 ` segher at gcc dot gnu.org 2014-12-10 18:34 ` segher at gcc dot gnu.org 2014-12-10 18:36 ` segher at gcc dot gnu.org 2014-12-10 18:38 ` segher at gcc dot gnu.org 2014-12-12 21:20 ` pthaugen at gcc dot gnu.org 2015-01-02 2:16 ` segher at gcc dot gnu.org
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