Re: [committed] Add missing T register clobber for SH port
On Thu, 2020-03-26 at 12:38 -0600, Jeff Law wrote: > On Wed, 2020-03-25 at 23:10 -0400, Hans-Peter Nilsson wrote: > > On Wed, 25 Mar 2020, Jeff Law via Gcc-patches wrote: > > > > The patch you sent, as well as what you committed as r10-7383, > > was just a ChangeLog entry. > > > > > Bootstrapped on sh4-linux-gnu and sh4eb-linux-gnu. Regression testing in > > > progress (won't finish for ~12 hours). No new test as it's covered by > > > vector- > > > compare-1 in the testsuite. > > > > ...so I guess you've noticed by the time you read this. :] > :-) > > Here's the actual patch: > > commit 48817fbd7616f086ac7bb1dd38b862f78762c9b8 > Author: Jeff Law > Date: Wed Mar 25 14:33:08 2020 -0600 > > Fix vector-compare-1 regressions on sh4/sh4eb caused by pattern > clobbering T reg without expressing that in its RTL. > > PR rtl-optimization/90275 > * config/sh/sh.md (mov_neg_si_t): Clobber the T register in > the > pattern. And sadly, the only thing this fixed was the regressions recently flagged by the tester. It didn't fix any of the pre-existing failures. Sigh. jeff >
Re: [committed] Add missing T register clobber for SH port
On Wed, 2020-03-25 at 23:10 -0400, Hans-Peter Nilsson wrote:
> On Wed, 25 Mar 2020, Jeff Law via Gcc-patches wrote:
>
> The patch you sent, as well as what you committed as r10-7383,
> was just a ChangeLog entry.
>
> > Bootstrapped on sh4-linux-gnu and sh4eb-linux-gnu. Regression testing in
> > progress (won't finish for ~12 hours). No new test as it's covered by
> > vector-
> > compare-1 in the testsuite.
>
> ...so I guess you've noticed by the time you read this. :]
:-)
Here's the actual patch:
commit 48817fbd7616f086ac7bb1dd38b862f78762c9b8
Author: Jeff Law
Date: Wed Mar 25 14:33:08 2020 -0600
Fix vector-compare-1 regressions on sh4/sh4eb caused by pattern
clobbering T reg without expressing that in its RTL.
PR rtl-optimization/90275
* config/sh/sh.md (mov_neg_si_t): Clobber the T register in the
pattern.
diff --git a/gcc/config/sh/sh.md b/gcc/config/sh/sh.md
index 4a1797160cf..fc80278a395 100644
--- a/gcc/config/sh/sh.md
+++ b/gcc/config/sh/sh.md
@@ -8395,9 +8395,15 @@
;; Store (negated) T bit as all zeros or ones in a reg.
;; subcRn,Rn ! Rn = Rn - Rn - T; T = T
;; not Rn,Rn ! Rn = 0 - Rn
+;;
+;; Note the call to sh_split_treg_set_expr may clobber
+;; the T reg. We must express this, even though it's
+;; not immediately obvious this pattern changes the
+;; T register.
(define_insn_and_split "mov_neg_si_t"
[(set (match_operand:SI 0 "arith_reg_dest" "=r")
- (neg:SI (match_operand 1 "treg_set_expr")))]
+ (neg:SI (match_operand 1 "treg_set_expr")))
+ (clobber (reg:SI T_REG))]
"TARGET_SH1"
{
gcc_assert (t_reg_operand (operands[1], VOIDmode));
Re: [committed] Add missing T register clobber for SH port
On Wed, 25 Mar 2020, Jeff Law via Gcc-patches wrote: The patch you sent, as well as what you committed as r10-7383, was just a ChangeLog entry. > Bootstrapped on sh4-linux-gnu and sh4eb-linux-gnu. Regression testing in > progress (won't finish for ~12 hours). No new test as it's covered by vector- > compare-1 in the testsuite. ...so I guess you've noticed by the time you read this. :] brgds, H-P
[committed] Add missing T register clobber for SH port
Whee, more fallout from the pr90275 changes. Thankfully this time it's a target issue. The sh4/sh4eb ports are failing vector-compare-1 execution tests after the cse changes. They only run once a week, so this wasn't caught immediately and took some time to reproduce and analyze. Ultimately the problem is one define_insn_and_split which, when split, may clobber the T register. However, the define_insn_and_split does not show this in the insn pattern. This can lead to various passes assuming the previous value in the T register is still valid when in fact, it's going to be clobbered. The CSE changes made this scenario more likely and it showed up as execution failures in the sh4/sh4eb testsuite. All the other places where we use sh_split_treg_set_expr have the appropriate clobber of the T register. Bootstrapped on sh4-linux-gnu and sh4eb-linux-gnu. Regression testing in progress (won't finish for ~12 hours). No new test as it's covered by vector- compare-1 in the testsuite. Jeff commit eeb0c7c07133634eb5e98ba0348392684a763c95 Author: Jeff Law Date: Wed Mar 25 14:12:32 2020 -0600 Fix vector-compare-1 regressions on sh4/sh4eb caused by pattern clobbering T reg without expressing that in its RTL. PR rtl-optimization/90275 * config/sh/sh.md (mov_neg_si_t): Clobber the T register in the pattern. diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 06b06ab68de..3ad7a7aae0d 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2020-03-25 Jeff Law + + PR rtl-optimization/90275 + * config/sh/sh.md (mov_neg_si_t): Clobber the T register in the + pattern. + 2020-03-25 Jakub Jelinek PR target/94292
