From dd3d6a42fcd881b1f4f8fbd6cc82c1f14124b317 Mon Sep 17 00:00:00 2001 From: Andrew Burgess Date: Fri, 14 Apr 2017 22:14:34 +0100 Subject: [PATCH] arc: Fix for loop end detection We use a negative ID number to link together the doloop_begin and doloop_end instructions. This negative ID number is setup within doloop_begin, at this point the ID is stored into the loop end instruction (doloop_end_i) and placed into the doloop_begin_i instruction. In arc.c (arc_reorg) we extract the ID from the doloop_end_i instruction in order to find the matching doloop_begin_i instruction, though the ID is only used in some cases. Currently in arc_reorg when we extract the ID we negate it. This negation is invalid. The ID stored in both doloop_end_i and doloop_begin_i is already negative, the negation in arc_reorg means that if we need to use the ID to find the doloop_begin_i then we will never find it (as the IDs will never match). This commit removes the unneeded negation, moves the extraction of the ID into a more appropriately scoped block and adds a new test for this issue. gcc/ChangeLog: * config/arc/arc.c (arc_reorg): Move loop_end_id into a more local block, and do not negate it, the stored id is already negative. gcc/testsuite/ChangeLog: * gcc.target/arc/loop-1.c: New file. Co-Authored-By: Guy Benyei From-SVN: r246933 --- gcc/ChangeLog | 6 +++++ gcc/config/arc/arc.c | 5 ++-- gcc/testsuite/ChangeLog | 4 ++++ gcc/testsuite/gcc.target/arc/loop-1.c | 45 +++++++++++++++++++++++++++++++++++ 4 files changed, 58 insertions(+), 2 deletions(-) create mode 100644 gcc/testsuite/gcc.target/arc/loop-1.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 8c4728c..2807eb2 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,4 +1,10 @@ 2017-04-14 Andrew Burgess + Guy Benyei + + * config/arc/arc.c (arc_reorg): Move loop_end_id into a more local + block, and do not negate it, the stored id is already negative. + +2017-04-14 Andrew Burgess * config/arc/arc.md (doloop_begin_i): Use @pcl assembler syntax. diff --git a/gcc/config/arc/arc.c b/gcc/config/arc/arc.c index c8ffa1a..92fecad 100644 --- a/gcc/config/arc/arc.c +++ b/gcc/config/arc/arc.c @@ -6569,8 +6569,6 @@ arc_reorg (void) rtx_insn *lp_simple = NULL; rtx_insn *next = NULL; rtx op0 = XEXP (XVECEXP (PATTERN (insn), 0, 1), 0); - HOST_WIDE_INT loop_end_id - = -INTVAL (XEXP (XVECEXP (PATTERN (insn), 0, 4), 0)); int seen_label = 0; for (lp = prev; @@ -6581,6 +6579,9 @@ arc_reorg (void) if (!lp || !NONJUMP_INSN_P (lp) || dead_or_set_regno_p (lp, LP_COUNT)) { + HOST_WIDE_INT loop_end_id + = INTVAL (XEXP (XVECEXP (PATTERN (insn), 0, 4), 0)); + for (prev = next = insn, lp = NULL ; prev || next;) { if (prev) diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index a1d74b6..3de763f 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2017-04-14 Andrew Burgess + + * gcc.target/arc/loop-1.c: New file. + 2017-04-14 Michael Meissner PR target/80098 diff --git a/gcc/testsuite/gcc.target/arc/loop-1.c b/gcc/testsuite/gcc.target/arc/loop-1.c new file mode 100644 index 0000000..1afe8eb --- /dev/null +++ b/gcc/testsuite/gcc.target/arc/loop-1.c @@ -0,0 +1,45 @@ +/* { dg-do compile } */ +/* { dg-options "-O2" } */ + +/* This case would fail to make use of the zero-overhead loop + instruction at one time due to a bug. */ + +extern char a[]; + +struct some_t +{ + struct + { + int aaa; + short bbb; + char ccc; + char ddd; + } ppp[8]; + + int www[1]; +}; + +int b; + +void +some_function () +{ + struct some_t *tmp = (struct some_t *) a; + + while ((*tmp).ppp[b].ccc) + while(0); + + for (; b; b++) + { + if (tmp->ppp[b].ccc) + { + int c = tmp->ppp[b].bbb; + int d = tmp->ppp[b].aaa; + int e = d - tmp->www[c]; + if (e) + tmp->ppp[b].ddd = 1; + } + } +} + +/* { dg-final { scan-assembler "\[^\n\]+lp \\.L__GCC__" } } */ -- 2.7.4