1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
|
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;
+}
+
+
|
