gcc/gcc7-pr84064.patch

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2018-01-30 10:26:25 +00:00
2018-01-30 Jeff Law <law@redhat.com>
PR target/84064
* i386.c (ix86_adjust_stack_and_probe_stack_clash): New argument
INT_REGISTERS_SAVED. Check it prior to calling
get_scratch_register_on_entry.
(ix86_adjust_stack_and_probe): Similarly.
(ix86_emit_probe_stack_range): Similarly.
(ix86_expand_prologue): Corresponding changes.
* gcc.target/i386/pr84064: New test.
--- gcc/config/i386/i386.c
+++ gcc/config/i386/i386.c
@@ -12591,10 +12591,14 @@ release_scratch_register_on_entry (struct scratch_reg *sr)
This differs from the next routine in that it tries hard to prevent
attacks that jump the stack guard. Thus it is never allowed to allocate
more than PROBE_INTERVAL bytes of stack space without a suitable
- probe. */
+ probe.
+
+ INT_REGISTERS_SAVED is true if integer registers have already been
+ 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 (const HOST_WIDE_INT size,
+ const bool int_registers_saved)
{
struct machine_function *m = cfun->machine;
@@ -12700,6 +12704,12 @@ ix86_adjust_stack_and_probe_stack_clash (const HOST_WIDE_INT size)
}
else
{
+ /* We expect the GP registers to be saved when probes are used
+ as the probing sequences might need a scratch register and
+ the routine to allocate one assumes the integer registers
+ have already been saved. */
+ gcc_assert (int_registers_saved);
+
struct scratch_reg sr;
get_scratch_register_on_entry (&sr);
@@ -12758,10 +12768,14 @@ ix86_adjust_stack_and_probe_stack_clash (const HOST_WIDE_INT size)
emit_insn (gen_blockage ());
}
-/* Emit code to adjust the stack pointer by SIZE bytes while probing it. */
+/* Emit code to adjust the stack pointer by SIZE bytes while probing it.
+
+ INT_REGISTERS_SAVED is true if integer registers have already been
+ pushed on the stack. */
static void
-ix86_adjust_stack_and_probe (const HOST_WIDE_INT size)
+ix86_adjust_stack_and_probe (const HOST_WIDE_INT size,
+ const bool int_registers_saved)
{
/* We skip the probe for the first interval + a small dope of 4 words and
probe that many bytes past the specified size to maintain a protection
@@ -12822,6 +12836,12 @@ ix86_adjust_stack_and_probe (const HOST_WIDE_INT size)
equality test for the loop condition. */
else
{
+ /* We expect the GP registers to be saved when probes are used
+ as the probing sequences might need a scratch register and
+ the routine to allocate one assumes the integer registers
+ have already been saved. */
+ gcc_assert (int_registers_saved);
+
HOST_WIDE_INT rounded_size;
struct scratch_reg sr;
@@ -12949,10 +12969,14 @@ output_adjust_stack_and_probe (rtx reg)
}
/* Emit code to probe a range of stack addresses from FIRST to FIRST+SIZE,
- inclusive. These are offsets from the current stack pointer. */
+ inclusive. These are offsets from the current stack pointer.
+
+ INT_REGISTERS_SAVED is true if integer registers have already been
+ pushed on the stack. */
static void
-ix86_emit_probe_stack_range (HOST_WIDE_INT first, HOST_WIDE_INT size)
+ix86_emit_probe_stack_range (HOST_WIDE_INT first, HOST_WIDE_INT size,
+ const bool int_registers_saved)
{
/* See if we have a constant small number of probes to generate. If so,
that's the easy case. The run-time loop is made up of 6 insns in the
@@ -12980,6 +13004,12 @@ ix86_emit_probe_stack_range (HOST_WIDE_INT first, HOST_WIDE_INT size)
equality test for the loop condition. */
else
{
+ /* We expect the GP registers to be saved when probes are used
+ as the probing sequences might need a scratch register and
+ the routine to allocate one assumes the integer registers
+ have already been saved. */
+ gcc_assert (int_registers_saved);
+
HOST_WIDE_INT rounded_size, last;
struct scratch_reg sr;
@@ -13733,15 +13763,10 @@ ix86_expand_prologue (void)
&& (flag_stack_check == STATIC_BUILTIN_STACK_CHECK
|| flag_stack_clash_protection))
{
- /* We expect the GP registers to be saved when probes are used
- as the probing sequences might need a scratch register and
- the routine to allocate one assumes the integer registers
- have already been saved. */
- gcc_assert (int_registers_saved);
-
if (flag_stack_clash_protection)
{
- ix86_adjust_stack_and_probe_stack_clash (allocate);
+ ix86_adjust_stack_and_probe_stack_clash (allocate,
+ int_registers_saved);
allocate = 0;
}
else if (STACK_CHECK_MOVING_SP)
@@ -13749,7 +13774,7 @@ ix86_expand_prologue (void)
if (!(crtl->is_leaf && !cfun->calls_alloca
&& allocate <= get_probe_interval ()))
{
- ix86_adjust_stack_and_probe (allocate);
+ ix86_adjust_stack_and_probe (allocate, int_registers_saved);
allocate = 0;
}
}
@@ -13765,11 +13790,12 @@ ix86_expand_prologue (void)
if (crtl->is_leaf && !cfun->calls_alloca)
{
if (size > get_probe_interval ())
- ix86_emit_probe_stack_range (0, size);
+ ix86_emit_probe_stack_range (0, size, int_registers_saved);
}
else
ix86_emit_probe_stack_range (0,
- size + get_stack_check_protect ());
+ size + get_stack_check_protect (),
+ int_registers_saved);
}
else
{
@@ -13778,10 +13804,13 @@ ix86_expand_prologue (void)
if (size > get_probe_interval ()
&& size > get_stack_check_protect ())
ix86_emit_probe_stack_range (get_stack_check_protect (),
- size - get_stack_check_protect ());
+ (size
+ - get_stack_check_protect ()),
+ int_registers_saved);
}
else
- ix86_emit_probe_stack_range (get_stack_check_protect (), size);
+ ix86_emit_probe_stack_range (get_stack_check_protect (), size,
+ int_registers_saved);
}
}
}
--- gcc/testsuite/gcc.target/i386/pr84064.c
+++ gcc/testsuite/gcc.target/i386/pr84064.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -march=i686 -fstack-clash-protection" } */
+/* { dg-require-effective-target ia32 } */
+
+void
+f (void *p1, void *p2)
+{
+ __builtin_memcpy (p1, p2, 1000);
+}
+