diff options
| author | Christophe Lyon <christophe.lyon@linaro.org> | 2015-06-03 20:54:22 +0200 |
|---|---|---|
| committer | Christophe Lyon <christophe.lyon@linaro.org> | 2015-06-11 14:28:23 +0200 |
| commit | 4f3f1dceca5e6721589c18f2cfba5a8a0578e0e1 (patch) | |
| tree | 60180b6baf35c445da90425b6f39998a0731eb81 | |
| parent | 7a51a33e2c9198eee904c0bef98e93bae9d566e3 (diff) | |
2015-06-03 Christophe Lyon <christophe.lyon@linaro.org>
Backport from trunk r222306.
gcc/
2015-04-22 Hale Wang <hale.wang@arm.com>
Terry Guo <terry.guo@arm.com>
PR rtl-optimization/64818
* combine.c (can_combine_p): Don't combine user-specified
register if it is in an asm input.
gcc/testsuite/
2015-04-22 Hale Wang <hale.wang@arm.com>
Terry Guo <terry.guo@arm.com>
PR rtl-optimization/64818
* gcc.target/arm/pr64818.c: New test.
Change-Id: I54af9401607fd77807e5c49a07b1872b8b32b672
| -rw-r--r-- | gcc/combine.c | 9 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.target/arm/pr64818.c | 30 |
2 files changed, 39 insertions, 0 deletions
diff --git a/gcc/combine.c b/gcc/combine.c index 46cd6db62ad..0ce8b5fec09 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -1914,6 +1914,15 @@ can_combine_p (rtx_insn *insn, rtx_insn *i3, rtx_insn *pred ATTRIBUTE_UNUSED, set = expand_field_assignment (set); src = SET_SRC (set), dest = SET_DEST (set); + /* Do not eliminate user-specified register if it is in an + asm input because we may break the register asm usage defined + in GCC manual if allow to do so. + Be aware that this may cover more cases than we expect but this + should be harmless. */ + if (REG_P (dest) && REG_USERVAR_P (dest) && HARD_REGISTER_P (dest) + && extract_asm_operands (PATTERN (i3))) + return 0; + /* Don't eliminate a store in the stack pointer. */ if (dest == stack_pointer_rtx /* Don't combine with an insn that sets a register to itself if it has diff --git a/gcc/testsuite/gcc.target/arm/pr64818.c b/gcc/testsuite/gcc.target/arm/pr64818.c new file mode 100644 index 00000000000..bddd8462c69 --- /dev/null +++ b/gcc/testsuite/gcc.target/arm/pr64818.c @@ -0,0 +1,30 @@ +/* { dg-do compile } */ +/* { dg-options "-O1" } */ + +char temp[16]; +extern int foo1 (void); + +void foo (void) +{ + int i; + int len; + + while (1) + { + len = foo1 (); + register int a asm ("r0") = 5; + register char *b asm ("r1") = temp; + register int c asm ("r2") = len; + asm volatile ("mov %[r0], %[r0]\n mov %[r1], %[r1]\n mov %[r2], %[r2]\n" + : "+m"(*b) + : [r0]"r"(a), [r1]"r"(b), [r2]"r"(c)); + + for (i = 0; i < len; i++) + { + if (temp[i] == 10) + return; + } + } +} + +/* { dg-final { scan-assembler "\[\\t \]+mov\ r1,\ r1" } } */ |