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| author | Wilco Dijkstra <wdijkstr@arm.com> | 2017-07-26 10:49:17 +0000 |
|---|---|---|
| committer | Wilco Dijkstra <wilco@gcc.gnu.org> | 2017-07-26 10:49:17 +0000 |
| commit | e17114487df7f90d8e015efad697a3cc93845b90 (patch) | |
| tree | 9f02cf54fd2ecd11c81775e3027fc7f58fa5b76d /gcc | |
| parent | 108c3c88d7273be093ff1431760bff5774381ac1 (diff) | |
| download | gcc-e17114487df7f90d8e015efad697a3cc93845b90.zip gcc-e17114487df7f90d8e015efad697a3cc93845b90.tar.gz gcc-e17114487df7f90d8e015efad697a3cc93845b90.tar.bz2 | |
Fix PR46932: Block auto increment on frame pointer
Block auto increment on frame pointer references. This is never
beneficial since the SFP expands into SP+C or FP+C during register
allocation. The generated code for the testcase is now as expected:
str x30, [sp, -32]!
strb w0, [sp, 31]
add x0, sp, 31
bl foo3
ldr x30, [sp], 32
ret
gcc/
PR middle-end/46932
* auto-inc-dec.c (parse_add_or_inc): Block autoinc on sfp.
gcc/testsuite/
PR middle-end/46932
* gcc.dg/pr46932.c: New testcase.
From-SVN: r250564
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/auto-inc-dec.c | 6 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/pr46932.c | 13 |
4 files changed, 29 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 2adda50..9bd8736 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2017-07-26 Wilco Dijkstra <wdijkstr@arm.com> + + PR middle-end/46932 + * auto-inc-dec.c (parse_add_or_inc): Block autoinc on sfp. + 2017-07-26 Martin Liska <mliska@suse.cz> PR sanitize/81186 diff --git a/gcc/auto-inc-dec.c b/gcc/auto-inc-dec.c index 91fa5cf..db1bd5b 100644 --- a/gcc/auto-inc-dec.c +++ b/gcc/auto-inc-dec.c @@ -769,6 +769,12 @@ parse_add_or_inc (rtx_insn *insn, bool before_mem) inc_insn.pat = pat; inc_insn.reg_res = SET_DEST (pat); inc_insn.reg0 = XEXP (SET_SRC (pat), 0); + + /* Block any auto increment of the frame pointer since it expands into + an addition and cannot be removed by copy propagation. */ + if (inc_insn.reg0 == frame_pointer_rtx) + return false; + if (rtx_equal_p (inc_insn.reg_res, inc_insn.reg0)) inc_insn.form = before_mem ? FORM_PRE_INC : FORM_POST_INC; else diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 0794a29..e7991a6 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2017-07-26 Wilco Dijkstra <wdijkstr@arm.com> + + PR middle-end/46932 + * gcc.dg/pr46932.c: New testcase. + 2017-07-26 Martin Liska <mliska@suse.cz> PR sanitize/81186 diff --git a/gcc/testsuite/gcc.dg/pr46932.c b/gcc/testsuite/gcc.dg/pr46932.c new file mode 100644 index 0000000..b96febc --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr46932.c @@ -0,0 +1,13 @@ +/* { dg-options "-O2 -fdump-rtl-auto_inc_dec" } */ + +/* Check that accesses based on the frame pointer do not + use auto increment. */ + +extern void foo(char*); +void t01(char t) +{ + char c = t; + foo(&c); +} + +/* { dg-final { scan-rtl-dump-not "success" "auto_inc_dec" } } */ |