| Message ID | 20150204161650.GA26675@intel.com |
|---|---|
| State | New |
| Headers | show |
On 2015-02-04 11:16 AM, H.J. Lu wrote: > When hard frame pointer isn't needed, the register for hard frame pointer > may be reused. This patch clears alignment on hard frame pointer if hard > frame pointer isn't needed. OK for trunk after bootstrap and test on > Linux/x86-64? LRA can set up frame_pointer_needed in some complicated cases (in lra-eliminations.c::setup_can_eliminate). So I'd reset REGNO_POINTER_ALIGN in setup_can_eleminate for any case even although without the change the patch is safe. So, H.J., if you add resetting REGNO_POINTER_ALIGN in setup_can_eliminate, the patch is automatically approved. > Thanks. > > H.J. > -- > gcc/ > > PR rtl-optimization/64905 > * ira.c (ira_setup_eliminable_regset): Clear hard frame pointer > alignment if it isn't needed. > > gcc/testsuite/ > > PR rtl-optimization/64905 > * gcc.target/i386/pr64905.c: New file. > --- > gcc/ira.c | 2 ++ > gcc/testsuite/gcc.target/i386/pr64905.c | 22 ++++++++++++++++++++++ > 2 files changed, 24 insertions(+) > create mode 100644 gcc/testsuite/gcc.target/i386/pr64905.c > >
diff --git a/gcc/ira.c b/gcc/ira.c index ea2b69f..a7cf476 100644 --- a/gcc/ira.c +++ b/gcc/ira.c @@ -2313,6 +2313,8 @@ ira_setup_eliminable_regset (void) if (frame_pointer_needed) df_set_regs_ever_live (HARD_FRAME_POINTER_REGNUM, true); + else + REGNO_POINTER_ALIGN (HARD_FRAME_POINTER_REGNUM) = 0; COPY_HARD_REG_SET (ira_no_alloc_regs, no_unit_alloc_regs); CLEAR_HARD_REG_SET (eliminable_regset); diff --git a/gcc/testsuite/gcc.target/i386/pr64905.c b/gcc/testsuite/gcc.target/i386/pr64905.c new file mode 100644 index 0000000..bc87d85 --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr64905.c @@ -0,0 +1,22 @@ +/* { dg-do compile { target { ! ia32 } } } */ +/* { dg-options "-Os -ffixed-rax -ffixed-rbx -ffixed-rcx -ffixed-rdx -ffixed-rdi -ffixed-rsi -ffixed-r8 -ffixed-r9 -ffixed-r10 -ffixed-r11 -ffixed-r12 -ffixed-r13 -ffixed-r14 -ffixed-r15" } */ +/* { dg-final { scan-assembler-not "movl\[ \t\]0\\(%.*\\), %.*" } } */ + +typedef unsigned short uint16_t; +uint16_t a_global; + +void __attribute__ ((noinline)) +function (uint16_t **a_p) +{ + // unaligned access by address in %rbp: mov 0x0(%rbp),%ebp + a_global = **a_p; +} + +int main(int argc, char **argv) +{ + uint16_t array [4] = { 1, 2, 3, 4 }; + uint16_t *array_elem_p = &array [3]; + + function (&array_elem_p); + return 0; +}