[Bug rtl-optimization/99863] [10 Regression] wrong code with -O -fno-tree-forwprop -mno-sse2 since r10-7268-g529ea7d9596b26ba
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99863 --- Comment #24 from CVS Commits --- The releases/gcc-8 branch has been updated by Jakub Jelinek : https://gcc.gnu.org/g:e1ef85b4f29e04e97f2ac0998bfd62bac50428b9 commit r8-10904-ge1ef85b4f29e04e97f2ac0998bfd62bac50428b9 Author: Jakub Jelinek Date: Sat Apr 3 10:07:09 2021 +0200 dse: Fix up hard reg conflict checking in replace_read [PR99863] Since PR37922 fix RTL DSE has hard register conflict checking in replace_read, so that if the replacement sequence sets (or typically just clobbers) some hard register (usually condition codes) we verify that hard register is not live. Unfortunately, it compares the hard reg set clobbered/set by the sequence (regs_set) against the currently live hard register set, but it then emits the insn sequence not at the current insn position, but before store_insn->insn. So, we should not compare against the current live hard register set, but against the hard register live set at the point of the store insn. Fortunately, we already have that remembered in store_insn->fixed_regs_live. In addition to bootstrapping/regtesting this patch on x86_64-linux and i686-linux, I've also added statistics gathering and it seems the only place where we end up rejecting the replace_read is the newly added testcase (the PR37922 is no longer effective at that) and fixed_regs_live has been always non-NULL at the if (store_insn->fixed_regs_live) spot. Rather than having there an assert, I chose to just keep regs_set as is, which means in that hypothetical case where fixed_regs_live wouldn't be computed for some store we'd still accept sequences that don't clobber/set any hard registers and just punt on those that clobber/set those. 2021-04-03 Jakub Jelinek PR rtl-optimization/99863 * dse.c (replace_read): Drop regs_live argument. Instead of regs_live, use store_insn->fixed_regs_live if non-NULL, otherwise punt if insns sequence clobbers or sets any hard registers. * gcc.target/i386/pr99863.c: New test. (cherry picked from commit 7a2f91d413eb7a3eb0ba52c7ac9618a35addd12a)
[Bug rtl-optimization/99863] [10 Regression] wrong code with -O -fno-tree-forwprop -mno-sse2 since r10-7268-g529ea7d9596b26ba
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99863 --- Comment #23 from CVS Commits --- The releases/gcc-9 branch has been updated by Jakub Jelinek : https://gcc.gnu.org/g:e9d56fab891afa3d40ed2ad75264c09aee65ab88 commit r9-9441-ge9d56fab891afa3d40ed2ad75264c09aee65ab88 Author: Jakub Jelinek Date: Sat Apr 3 10:07:09 2021 +0200 dse: Fix up hard reg conflict checking in replace_read [PR99863] Since PR37922 fix RTL DSE has hard register conflict checking in replace_read, so that if the replacement sequence sets (or typically just clobbers) some hard register (usually condition codes) we verify that hard register is not live. Unfortunately, it compares the hard reg set clobbered/set by the sequence (regs_set) against the currently live hard register set, but it then emits the insn sequence not at the current insn position, but before store_insn->insn. So, we should not compare against the current live hard register set, but against the hard register live set at the point of the store insn. Fortunately, we already have that remembered in store_insn->fixed_regs_live. In addition to bootstrapping/regtesting this patch on x86_64-linux and i686-linux, I've also added statistics gathering and it seems the only place where we end up rejecting the replace_read is the newly added testcase (the PR37922 is no longer effective at that) and fixed_regs_live has been always non-NULL at the if (store_insn->fixed_regs_live) spot. Rather than having there an assert, I chose to just keep regs_set as is, which means in that hypothetical case where fixed_regs_live wouldn't be computed for some store we'd still accept sequences that don't clobber/set any hard registers and just punt on those that clobber/set those. 2021-04-03 Jakub Jelinek PR rtl-optimization/99863 * dse.c (replace_read): Drop regs_live argument. Instead of regs_live, use store_insn->fixed_regs_live if non-NULL, otherwise punt if insns sequence clobbers or sets any hard registers. * gcc.target/i386/pr99863.c: New test. (cherry picked from commit 7a2f91d413eb7a3eb0ba52c7ac9618a35addd12a)
[Bug rtl-optimization/99863] [10 Regression] wrong code with -O -fno-tree-forwprop -mno-sse2 since r10-7268-g529ea7d9596b26ba
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99863 Jakub Jelinek changed: What|Removed |Added Resolution|--- |FIXED Status|ASSIGNED|RESOLVED --- Comment #22 from Jakub Jelinek --- Fixed.
[Bug rtl-optimization/99863] [10 Regression] wrong code with -O -fno-tree-forwprop -mno-sse2 since r10-7268-g529ea7d9596b26ba
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99863 --- Comment #21 from CVS Commits --- The releases/gcc-10 branch has been updated by Jakub Jelinek : https://gcc.gnu.org/g:7a2f91d413eb7a3eb0ba52c7ac9618a35addd12a commit r10-9721-g7a2f91d413eb7a3eb0ba52c7ac9618a35addd12a Author: Jakub Jelinek Date: Sat Apr 3 10:07:09 2021 +0200 dse: Fix up hard reg conflict checking in replace_read [PR99863] Since PR37922 fix RTL DSE has hard register conflict checking in replace_read, so that if the replacement sequence sets (or typically just clobbers) some hard register (usually condition codes) we verify that hard register is not live. Unfortunately, it compares the hard reg set clobbered/set by the sequence (regs_set) against the currently live hard register set, but it then emits the insn sequence not at the current insn position, but before store_insn->insn. So, we should not compare against the current live hard register set, but against the hard register live set at the point of the store insn. Fortunately, we already have that remembered in store_insn->fixed_regs_live. In addition to bootstrapping/regtesting this patch on x86_64-linux and i686-linux, I've also added statistics gathering and it seems the only place where we end up rejecting the replace_read is the newly added testcase (the PR37922 is no longer effective at that) and fixed_regs_live has been always non-NULL at the if (store_insn->fixed_regs_live) spot. Rather than having there an assert, I chose to just keep regs_set as is, which means in that hypothetical case where fixed_regs_live wouldn't be computed for some store we'd still accept sequences that don't clobber/set any hard registers and just punt on those that clobber/set those. 2021-04-03 Jakub Jelinek PR rtl-optimization/99863 * dse.c (replace_read): Drop regs_live argument. Instead of regs_live, use store_insn->fixed_regs_live if non-NULL, otherwise punt if insns sequence clobbers or sets any hard registers. * gcc.target/i386/pr99863.c: New test. (cherry picked from commit 9c7473688e78dc41fd4312a983453df195dd7786)
[Bug rtl-optimization/99863] [10 Regression] wrong code with -O -fno-tree-forwprop -mno-sse2 since r10-7268-g529ea7d9596b26ba
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99863 Richard Biener changed: What|Removed |Added Target Milestone|10.3|10.4 --- Comment #20 from Richard Biener --- GCC 10.3 is being released, retargeting bugs to GCC 10.4.
[Bug rtl-optimization/99863] [10 Regression] wrong code with -O -fno-tree-forwprop -mno-sse2 since r10-7268-g529ea7d9596b26ba
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99863 Jakub Jelinek changed: What|Removed |Added Summary|[10/11 Regression] wrong|[10 Regression] wrong code |code with -O|with -O -fno-tree-forwprop |-fno-tree-forwprop |-mno-sse2 since |-mno-sse2 since |r10-7268-g529ea7d9596b26ba |r10-7268-g529ea7d9596b26ba | --- Comment #19 from Jakub Jelinek --- Fixed on the trunk so far.
