[Bug target/63949] Aarch64 instruction combiner does not optimize subsi_sxth function as expected (gcc.target/aarch64/extend.c fails)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63949 vekumar at gcc dot gnu.org changed: What|Removed |Added Status|ASSIGNED|RESOLVED

[Bug target/63949] Aarch64 instruction combiner does not optimize subsi_sxth function as expected (gcc.target/aarch64/extend.c fails)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63949 --- Comment #11 from Andrew Pinski pinskia at gcc dot gnu.org --- https://gcc.gnu.org/ml/gcc-patches/2015-01/msg01020.html

[Bug target/63949] Aarch64 instruction combiner does not optimize subsi_sxth function as expected (gcc.target/aarch64/extend.c fails)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63949 Ramana Radhakrishnan ramana at gcc dot gnu.org changed: What|Removed |Added Status|NEW |ASSIGNED

[Bug target/63949] Aarch64 instruction combiner does not optimize subsi_sxth function as expected (gcc.target/aarch64/extend.c fails)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63949 --- Comment #10 from vekumar at gcc dot gnu.org --- (In reply to Segher Boessenkool from comment #9) A MULT by a constant power of 2 is not canonical RTL (well, not what simplify_rtx would give you); combine shouldn't generate this. In that

[Bug target/63949] Aarch64 instruction combiner does not optimize subsi_sxth function as expected (gcc.target/aarch64/extend.c fails)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63949 Segher Boessenkool segher at gcc dot gnu.org changed: What|Removed |Added CC||segher at

[Bug target/63949] Aarch64 instruction combiner does not optimize subsi_sxth function as expected (gcc.target/aarch64/extend.c fails)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63949 --- Comment #8 from vekumar at gcc dot gnu.org --- This is complete patch for the first approach that I took (comment 6). This patch fixes issues I faced while testing. But I have added extra patterns to cater the sign extended operands with left

[Bug target/63949] Aarch64 instruction combiner does not optimize subsi_sxth function as expected (gcc.target/aarch64/extend.c fails)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63949 --- Comment #7 from vekumar at gcc dot gnu.org --- I ran GCC tests against the patch found one failure. int adds_shift_ext ( long long a, int b, int c) { long long d = (a + ((long long)b 3)); if (d == 0) return a + c; else

[Bug target/63949] Aarch64 instruction combiner does not optimize subsi_sxth function as expected (gcc.target/aarch64/extend.c fails)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63949 --- Comment #6 from vekumar at gcc dot gnu.org --- In the function make_compound_operation, there a check /* See if we have operations between an ASHIFTRT and an ASHIFT. If so, try to merge the shifts into a SIGN_EXTEND. We

[Bug target/63949] Aarch64 instruction combiner does not optimize subsi_sxth function as expected (gcc.target/aarch64/extend.c fails)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63949 --- Comment #4 from vekumar at gcc dot gnu.org --- (In reply to Richard Earnshaw from comment #3) make_extraction is unable to generate bit-field extractions in more than one mode. This causes the extractions that it does generate to be

[Bug target/63949] Aarch64 instruction combiner does not optimize subsi_sxth function as expected (gcc.target/aarch64/extend.c fails)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63949 --- Comment #5 from vekumar at gcc dot gnu.org --- Richard, what the function get_best_reg_extraction_insn is supposed to do in make_extraction ?

[Bug target/63949] Aarch64 instruction combiner does not optimize subsi_sxth function as expected (gcc.target/aarch64/extend.c fails)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63949 --- Comment #3 from Richard Earnshaw rearnsha at gcc dot gnu.org --- make_extraction is unable to generate bit-field extractions in more than one mode. This causes the extractions that it does generate to be wrapped in subregs when SImode