commit 14041afe24556efd5845564aa183b6451fd9d6cc
Author: law <law@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Thu Feb 1 16:22:56 2018 +0000
PR target/84128
* config/i386/i386.c (release_scratch_register_on_entry): Add new
OFFSET and RELEASE_VIA_POP arguments. Use SP+OFFSET to restore
the scratch if RELEASE_VIA_POP is false.
(ix86_adjust_stack_and_probe_stack_clash): Un-constify SIZE.
If we have to save a temporary register, decrement SIZE appropriately.
Pass new arguments to release_scratch_register_on_entry.
(ix86_adjust_stack_and_probe): Likewise.
(ix86_emit_probe_stack_range): Pass new arguments to
release_scratch_register_on_entry.
PR target/84128
* gcc.target/i386/pr84128.c: New test.
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 2fe2a0c..c25d26c 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -10182,22 +10182,39 @@ get_scratch_register_on_entry (struct scratch_reg *sr)
}
}
-/* Release a scratch register obtained from the preceding function. */
+/* Release a scratch register obtained from the preceding function.
+
+ If RELEASE_VIA_POP is true, we just pop the register off the stack
+ to release it. This is what non-Linux systems use with -fstack-check.
+
+ Otherwise we use OFFSET to locate the saved register and the
+ allocated stack space becomes part of the local frame and is
+ deallcated by the epilogue. */
static void
-release_scratch_register_on_entry (struct scratch_reg *sr)
+release_scratch_register_on_entry (struct scratch_reg *sr, HOST_WIDE_INT offset,
+ bool release_via_pop)
{
if (sr->saved)
{
- struct machine_function *m = cfun->machine;
- rtx x, insn = emit_insn (gen_pop (sr->reg));
+ if (release_via_pop)
+ {
+ struct machine_function *m = cfun->machine;
+ rtx x, insn = emit_insn (gen_pop (sr->reg));
- /* The RTX_FRAME_RELATED_P mechanism doesn't know about pop. */
- RTX_FRAME_RELATED_P (insn) = 1;
- x = gen_rtx_PLUS (Pmode, stack_pointer_rtx, GEN_INT (UNITS_PER_WORD));
- x = gen_rtx_SET (VOIDmode, stack_pointer_rtx, x);
- add_reg_note (insn, REG_FRAME_RELATED_EXPR, x);
- m->fs.sp_offset -= UNITS_PER_WORD;
+ /* The RTX FRAME_RELATED_P mechanism doesn't know about pop. */
+ RTX_FRAME_RELATED_P (insn) = 1;
+ x = gen_rtx_PLUS (Pmode, stack_pointer_rtx, GEN_INT (UNITS_PER_WORD));
+ x = gen_rtx_SET (VOIDmode, stack_pointer_rtx, x);
+ add_reg_note (insn, REG_FRAME_RELATED_EXPR, x);
+ m->fs.sp_offset -= UNITS_PER_WORD;
+ }
+ else
+ {
+ rtx x = gen_rtx_PLUS (Pmode, stack_pointer_rtx, GEN_INT (offset));
+ x = gen_rtx_SET (VOIDmode, sr->reg, gen_rtx_MEM (word_mode, x));
+ emit_insn (x);
+ }
}
}
@@ -10212,7 +10229,7 @@ release_scratch_register_on_entry (struct scratch_reg *sr)
pushed on the stack. */
static void
-ix86_adjust_stack_and_probe_stack_clash (const HOST_WIDE_INT size,
+ix86_adjust_stack_and_probe_stack_clash (HOST_WIDE_INT size,
const bool int_registers_saved)
{
struct machine_function *m = cfun->machine;
@@ -10331,6 +10348,12 @@ ix86_adjust_stack_and_probe_stack_clash (const HOST_WIDE_INT size,
struct scratch_reg sr;
get_scratch_register_on_entry (&sr);
+ /* If we needed to save a register, then account for any space
+ that was pushed (we are not going to pop the register when
+ we do the restore). */
+ if (sr.saved)
+ size -= UNITS_PER_WORD;
+
/* Step 1: round SIZE down to a multiple of the interval. */
HOST_WIDE_INT rounded_size = size & -probe_interval;
@@ -10379,7 +10402,9 @@ ix86_adjust_stack_and_probe_stack_clash (const HOST_WIDE_INT size,
m->fs.cfa_reg == stack_pointer_rtx);
dump_stack_clash_frame_info (PROBE_LOOP, size != rounded_size);
- release_scratch_register_on_entry (&sr);
+ /* This does not deallocate the space reserved for the scratch
+ register. That will be deallocated in the epilogue. */
+ release_scratch_register_on_entry (&sr, size, false);
}
/* Make sure nothing is scheduled before we are done. */
@@ -10392,7 +10417,7 @@ ix86_adjust_stack_and_probe_stack_clash (const HOST_WIDE_INT size,
pushed on the stack. */
static void
-ix86_adjust_stack_and_probe (const HOST_WIDE_INT size,
+ix86_adjust_stack_and_probe (HOST_WIDE_INT size,
const bool int_registers_saved)
{
/* We skip the probe for the first interval + a small dope of 4 words and
@@ -10465,6 +10490,11 @@ ix86_adjust_stack_and_probe (const HOST_WIDE_INT size,
get_scratch_register_on_entry (&sr);
+ /* If we needed to save a register, then account for any space
+ that was pushed (we are not going to pop the register when
+ we do the restore). */
+ if (sr.saved)
+ size -= UNITS_PER_WORD;
/* Step 1: round SIZE to the previous multiple of the interval. */
@@ -10516,7 +10546,9 @@ ix86_adjust_stack_and_probe (const HOST_WIDE_INT size,
(get_probe_interval ()
+ dope))));
- release_scratch_register_on_entry (&sr);
+ /* This does not deallocate the space reserved for the scratch
+ register. That will be deallocated in the epilogue. */
+ release_scratch_register_on_entry (&sr, size, false);
}
gcc_assert (cfun->machine->fs.cfa_reg != stack_pointer_rtx);
@@ -10669,7 +10701,7 @@ ix86_emit_probe_stack_range (HOST_WIDE_INT first, HOST_WIDE_INT size,
sr.reg),
rounded_size - size));
- release_scratch_register_on_entry (&sr);
+ release_scratch_register_on_entry (&sr, size, true);
}
/* Make sure nothing is scheduled before we are done. */
diff --git a/gcc/testsuite/gcc.target/i386/pr84128.c b/gcc/testsuite/gcc.target/i386/pr84128.c
new file mode 100644
index 0000000..a8323fd
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr84128.c
@@ -0,0 +1,30 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -march=i686 -mtune=generic -fstack-clash-protection" } */
+/* { dg-require-effective-target ia32 } */
+
+__attribute__ ((noinline, noclone, weak, regparm (3)))
+int
+f1 (long arg0, int (*pf) (long, void *))
+{
+ unsigned char buf[32768];
+ return pf (arg0, buf);
+}
+
+__attribute__ ((noinline, noclone, weak))
+int
+f2 (long arg0, void *ignored)
+{
+ if (arg0 != 17)
+ __builtin_abort ();
+ return 19;
+}
+
+int
+main (void)
+{
+ if (f1 (17, f2) != 19)
+ __builtin_abort ();
+ return 0;
+}
+
+