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| author | Segher Boessenkool <segher@kernel.crashing.org> | 2017-05-22 23:20:51 +0200 |
|---|---|---|
| committer | Segher Boessenkool <segher@gcc.gnu.org> | 2017-05-22 23:20:51 +0200 |
| commit | 2ea0d750147582b5d7bf405dce36f864618eacbd (patch) | |
| tree | 34cc1dd5be60d131c6db256516f0ff7f4e71c648 /gcc | |
| parent | 25b8168681bb5d1bc5e74c54b8f4cad635636ff1 (diff) | |
| download | gcc-2ea0d750147582b5d7bf405dce36f864618eacbd.zip gcc-2ea0d750147582b5d7bf405dce36f864618eacbd.tar.gz gcc-2ea0d750147582b5d7bf405dce36f864618eacbd.tar.bz2 | |
cfgcleanup: Ignore clobbers in bb_is_just_return
The function bb_is_just_return finds if the BB it is asked about does
just a return and nothing else. It currently does not allow clobbers
in the block either, which we of course can allow just fine.
This patch changes that.
* cfgcleanup.c (bb_is_just_return): Allow CLOBBERs.
gcc/testsuite/
From-SVN: r248351
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 4 | ||||
| -rw-r--r-- | gcc/cfgcleanup.c | 14 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 4 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.target/powerpc/conditional-return.c | 15 |
4 files changed, 31 insertions, 6 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 7bdd6f2..713654d 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,7 @@ +2017-05-22 Segher Boessenkool <segher@kernel.crashing.org> + + * cfgcleanup.c (bb_is_just_return): Allow CLOBBERs. + 2017-05-22 Jakub Jelinek <jakub@redhat.com> PR middle-end/80809 diff --git a/gcc/cfgcleanup.c b/gcc/cfgcleanup.c index f68a964..3e1406c 100644 --- a/gcc/cfgcleanup.c +++ b/gcc/cfgcleanup.c @@ -2666,7 +2666,7 @@ trivially_empty_bb_p (basic_block bb) /* Return true if BB contains just a return and possibly a USE of the return value. Fill in *RET and *USE with the return and use insns - if any found, otherwise NULL. */ + if any found, otherwise NULL. All CLOBBERs are ignored. */ static bool bb_is_just_return (basic_block bb, rtx_insn **ret, rtx_insn **use) @@ -2680,13 +2680,15 @@ bb_is_just_return (basic_block bb, rtx_insn **ret, rtx_insn **use) FOR_BB_INSNS (bb, insn) if (NONDEBUG_INSN_P (insn)) { - if (!*ret && ANY_RETURN_P (PATTERN (insn))) + rtx pat = PATTERN (insn); + + if (!*ret && ANY_RETURN_P (pat)) *ret = insn; - else if (!*ret && !*use && GET_CODE (PATTERN (insn)) == USE - && REG_P (XEXP (PATTERN (insn), 0)) - && REG_FUNCTION_VALUE_P (XEXP (PATTERN (insn), 0))) + else if (!*ret && !*use && GET_CODE (pat) == USE + && REG_P (XEXP (pat, 0)) + && REG_FUNCTION_VALUE_P (XEXP (pat, 0))) *use = insn; - else + else if (GET_CODE (pat) != CLOBBER) return false; } diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 08cfe12..c55b0ee 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2017-05-22 Segher Boessenkool <segher@kernel.crashing.org> + + * gcc.target/powerpc/conditional-return.c: New testcase. + 2017-05-22 Bill Schmidt <wschmidt@linux.vnet.ibm.com> * gcc.target/powerpc/p8-vec-xl-xst.c: Fix target string to diff --git a/gcc/testsuite/gcc.target/powerpc/conditional-return.c b/gcc/testsuite/gcc.target/powerpc/conditional-return.c new file mode 100644 index 0000000..6b3ef5f --- /dev/null +++ b/gcc/testsuite/gcc.target/powerpc/conditional-return.c @@ -0,0 +1,15 @@ +/* Check that a conditional return is used. */ + +/* { dg-do compile } */ +/* { dg-options "-O2 -w" } */ + +/* { dg-final { scan-assembler {\mbeqlr\M} } } */ + + +int f(int x) +{ + if (x) + return x + 31; + + return; +} |