Agree. Let't stop at first insn after entry block notes.
As for the test it looks like mcount is general i?86 name.
Bootstrap and make check are in progress.
2014-10-28 Evgeny Stupachenko <evstu...@gmail.com>
gcc/testsuite
PR target/63534
* gcc.target/i386/mcount_pic.c: New.
gcc/
PR target/63534
* config/i386/i386.c (ix86_init_pic_reg): Emit SET_GOT to
REAL_PIC_OFFSET_TABLE_REGNUM for mcount profiling.
(ix86_save_reg): Save REAL_PIC_OFFSET_TABLE_REGNUM when profiling
using mcount in 32bit PIC mode.
(ix86_elim_entry_set_got): New.
(ix86_expand_prologue): For the mcount profiling emit new SET_GOT
in PROLOGUE, delete initial if possible.
2014-10-22 Evgeny Stupachenko <evstu...@gmail.com>
PR rtl-optimization/63618
* gcc.target/i386/pr63618.c: New.
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 6235c4f..a38bc33 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -6190,8 +6190,15 @@ ix86_init_pic_reg (void)
}
else
{
- rtx insn = emit_insn (gen_set_got (pic_offset_table_rtx));
+ /* If there is future mcount call in the function it is more profitable
+ to emit SET_GOT into ABI defined REAL_PIC_OFFSET_TABLE_REGNUM. */
+ rtx reg = crtl->profile
+ ? gen_rtx_REG (Pmode, REAL_PIC_OFFSET_TABLE_REGNUM)
+ : pic_offset_table_rtx;
+ rtx insn = emit_insn (gen_set_got (reg));
RTX_FRAME_RELATED_P (insn) = 1;
+ if (crtl->profile)
+ emit_move_insn (pic_offset_table_rtx, reg);
add_reg_note (insn, REG_CFA_FLUSH_QUEUE, NULL_RTX);
}
@@ -9471,15 +9478,23 @@ ix86_select_alt_pic_regnum (void)
static bool
ix86_save_reg (unsigned int regno, bool maybe_eh_return)
{
- if (pic_offset_table_rtx
- && !ix86_use_pseudo_pic_reg ()
- && regno == REAL_PIC_OFFSET_TABLE_REGNUM
- && (df_regs_ever_live_p (REAL_PIC_OFFSET_TABLE_REGNUM)
- || crtl->profile
- || crtl->calls_eh_return
- || crtl->uses_const_pool
- || cfun->has_nonlocal_label))
- return ix86_select_alt_pic_regnum () == INVALID_REGNUM;
+ if (regno == REAL_PIC_OFFSET_TABLE_REGNUM
+ && pic_offset_table_rtx)
+ {
+ if (ix86_use_pseudo_pic_reg ())
+ {
+ /* REAL_PIC_OFFSET_TABLE_REGNUM used by call to
+ _mcount in prologue. */
+ if (!TARGET_64BIT && flag_pic && crtl->profile)
+ return true;
+ }
+ else if (df_regs_ever_live_p (REAL_PIC_OFFSET_TABLE_REGNUM)
+ || crtl->profile
+ || crtl->calls_eh_return
+ || crtl->uses_const_pool
+ || cfun->has_nonlocal_label)
+ return ix86_select_alt_pic_regnum () == INVALID_REGNUM;
+ }
if (crtl->calls_eh_return && maybe_eh_return)
{
@@ -10818,6 +10833,30 @@ ix86_finalize_stack_realign_flags (void)
crtl->stack_realign_finalized = true;
}
+/* Delete SET_GOT right after entry block if it is allocated to reg. */
+
+static void
+ix86_elim_entry_set_got (rtx reg)
+{
+ basic_block bb = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb;
+ rtx_insn *c_insn;
+ FOR_BB_INSNS (bb, c_insn)
+ if (GET_CODE (c_insn) != NOTE)
+ break;
+ if (NONJUMP_INSN_P (c_insn))
+ {
+ rtx pat = PATTERN (c_insn);
+ if (GET_CODE (pat) == PARALLEL)
+ {
+ rtx vec = XVECEXP (pat, 0, 0);
+ if (GET_CODE (vec) == SET
+ && XINT (XEXP (vec, 1), 1) == UNSPEC_SET_GOT
+ && REGNO (XEXP (vec, 0)) == REGNO (reg))
+ delete_insn (c_insn);
+ }
+ }
+}
+
/* Expand the prologue into a bunch of separate insns. */
void
@@ -11271,6 +11310,20 @@ ix86_expand_prologue (void)
if (!sse_registers_saved)
ix86_emit_save_sse_regs_using_mov (frame.sse_reg_save_offset);
+ /* For the mcount profiling on 32 bit PIC mode we need to emit SET_GOT
+ in PROLOGUE. */
+ if (!TARGET_64BIT && pic_offset_table_rtx && crtl->profile && !flag_fentry)
+ {
+ rtx pic = gen_rtx_REG (Pmode, REAL_PIC_OFFSET_TABLE_REGNUM);
+ insn = emit_insn (gen_set_got (pic));
+ RTX_FRAME_RELATED_P (insn) = 1;
+ add_reg_note (insn, REG_CFA_FLUSH_QUEUE, NULL_RTX);
+ emit_insn (gen_prologue_use (pic));
+ /* Deleting already emmitted SET_GOT if exist and allocated to
+ REAL_PIC_OFFSET_TABLE_REGNUM. */
+ ix86_elim_entry_set_got (pic);
+ }
+
if (crtl->drap_reg && !crtl->stack_realign_needed)
{
/* vDRAP is setup but after reload it turns out stack realign
diff --git a/gcc/testsuite/gcc.target/i386/mcount_pic.c
b/gcc/testsuite/gcc.target/i386/mcount_pic.c
new file mode 100644
index 0000000..08ecd07
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/mcount_pic.c
@@ -0,0 +1,13 @@
+/* Test check correct mcount generation. */
+/* { dg-do run } */
+/* { dg-require-effective-target ia32 } */
+/* { dg-options "-O2 -fpic -p -save-temps" } */
+
+int main ()
+{
+ return 0;
+}
+
+/* { dg-final { scan-assembler "mcount" } } */
+/* { dg-final { scan-assembler "get_pc_thunk" } } */
+/* { dg-final { cleanup-saved-temps } } */
On Tue, Oct 28, 2014 at 4:36 PM, Jakub Jelinek <ja...@redhat.com> wrote:
> On Tue, Oct 28, 2014 at 04:10:12PM +0300, Evgeny Stupachenko wrote:
>> Thank you, Jakub.
>>
>> The following patch passed bootstrap, gcc make check and spec2000 with
>> "-p -m32 -fPIC".
>> Is it ok?
>>
>> ChangeLog:
>>
>> 2014-10-28 Evgeny Stupachenko <evstu...@gmail.com>
>>
>> gcc/testsuite
>> * gcc.target/i386/mcount_pic.c: New.
>>
>> gcc/
>
> Please mention
> PR target/63534
> in the ChangeLog entry.
>
>> @@ -10818,6 +10833,36 @@ ix86_finalize_stack_realign_flags (void)
>> crtl->stack_realign_finalized = true;
>> }
>>
>> +/* Delete first SET_GOT allocated to reg. */
>> +
>> +static void
>> +ix86_elim_set_got (rtx reg)
>> +{
>> + basic_block bb;
>> + FOR_EACH_BB_FN (bb, cfun)
>> + {
>> + rtx_insn *c_insn;
>> + FOR_BB_INSNS (bb, c_insn)
>> + {
>> + if (GET_CODE (c_insn) == INSN)
>> + {
>> + rtx pat = PATTERN (c_insn);
>> + if (GET_CODE (pat) == PARALLEL)
>> + {
>> + rtx vec = XVECEXP (pat, 0, 0);
>> + if (GET_CODE (vec) == SET
>> + && XINT (XEXP (vec, 1), 1) == UNSPEC_SET_GOT
>> + && REGNO (XEXP (vec, 0)) == REGNO (reg))
>> + {
>> + delete_insn (c_insn);
>> + return;
>> + }
>> + }
>> + }
>> + }
>> + }
>> +}
>> +
>
> This is unsafe. What I meant is to just remove set_got insn
> that is at the beginning of the first basic block (successor of
> entry bb), perhaps after some notes. You can perhaps generalize
> that a little bit and look at other insns in the first bb, as long
> as no NONDEBUG_INSN_P insn preceeding satisfy
> modified_in_p (reg, c_insn) or reg_referenced_p (reg, PATTERN (c_insn))
> or so. But certainly stop at the end of the first bb or at any
> real insn that might clobber/set %ebx or use it.
>
> Also, instead of GET_CODE (c_insn) == INSN please use
> NONJUMP_INSN_P (c_insn).
>
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.target/i386/mcount_pic.c
>> @@ -0,0 +1,12 @@
>> +/* Test check correct mcount generation. */
>> +/* { dg-do run } */
>> +/* { dg-require-effective-target ia32 } */
>> +/* { dg-options "-O2 -fpic -p -save-temps" } */
>> +
>> +int main()
>> +{
>> + return 0;
>> +}
>> +
>> +/* { dg-final { scan-assembler "mcount" } } */
>> +/* { dg-final { scan-assembler "get_pc_thunk" } } */
>
> Missing cleanup-save-temps. Is _mcount the name of the profiling routine
> on all i?86 targets?
>
> Jakub
