https://gcc.gnu.org/g:11902be7a57c0ccf03786aa0255fffaf0f54dbf9
commit r15-7573-g11902be7a57c0ccf03786aa0255fffaf0f54dbf9
Author: H.J. Lu <hjl.to...@gmail.com>
Date: Tue Mar 14 11:41:51 2023 -0700
x86: Properly find the maximum stack slot alignment
Don't assume that stack slots can only be accessed by stack or frame
registers. We first find all registers defined by stack or frame
registers. Then check memory accesses by such registers, including
stack and frame registers.
gcc/
PR target/109780
PR target/109093
* config/i386/i386.cc (ix86_update_stack_alignment): New.
(ix86_find_all_reg_use_1): Likewise.
(ix86_find_all_reg_use): Likewise.
(ix86_find_max_used_stack_alignment): Also check memory accesses
from registers defined by stack or frame registers.
gcc/testsuite/
PR target/109780
PR target/109093
* g++.target/i386/pr109780-1.C: New test.
* gcc.target/i386/pr109093-1.c: Likewise.
* gcc.target/i386/pr109780-1.c: Likewise.
* gcc.target/i386/pr109780-2.c: Likewise.
* gcc.target/i386/pr109780-3.c: Likewise.
Signed-off-by: H.J. Lu <hjl.to...@gmail.com>
Diff:
---
gcc/config/i386/i386.cc | 177 +++++++++++++++++++++++++----
gcc/testsuite/g++.target/i386/pr109780-1.C | 72 ++++++++++++
gcc/testsuite/gcc.target/i386/pr109093-1.c | 33 ++++++
gcc/testsuite/gcc.target/i386/pr109780-1.c | 14 +++
gcc/testsuite/gcc.target/i386/pr109780-2.c | 21 ++++
gcc/testsuite/gcc.target/i386/pr109780-3.c | 46 ++++++++
6 files changed, 342 insertions(+), 21 deletions(-)
diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index 3128973ba79c..fafd4a511a3c 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -8466,6 +8466,107 @@ output_probe_stack_range (rtx reg, rtx end)
return "";
}
+/* Update the maximum stack slot alignment from memory alignment in
+ PAT. */
+
+static void
+ix86_update_stack_alignment (rtx, const_rtx pat, void *data)
+{
+ /* This insn may reference stack slot. Update the maximum stack slot
+ alignment. */
+ subrtx_iterator::array_type array;
+ FOR_EACH_SUBRTX (iter, array, pat, ALL)
+ if (MEM_P (*iter))
+ {
+ unsigned int alignment = MEM_ALIGN (*iter);
+ unsigned int *stack_alignment
+ = (unsigned int *) data;
+ if (alignment > *stack_alignment)
+ *stack_alignment = alignment;
+ break;
+ }
+}
+
+/* Helper function for ix86_find_all_reg_use. */
+
+static void
+ix86_find_all_reg_use_1 (rtx set, HARD_REG_SET &stack_slot_access,
+ auto_bitmap &worklist)
+{
+ rtx dest = SET_DEST (set);
+ if (!REG_P (dest))
+ return;
+
+ rtx src = SET_SRC (set);
+ if (MEM_P (src) || CONST_SCALAR_INT_P (src))
+ return;
+
+ if (TEST_HARD_REG_BIT (stack_slot_access, REGNO (dest)))
+ return;
+
+ /* Add this register to stack_slot_access. */
+ add_to_hard_reg_set (&stack_slot_access, Pmode, REGNO (dest));
+ bitmap_set_bit (worklist, REGNO (dest));
+}
+
+/* Find all registers defined with REG. */
+
+static void
+ix86_find_all_reg_use (HARD_REG_SET &stack_slot_access,
+ unsigned int reg, auto_bitmap &worklist)
+{
+ for (df_ref ref = DF_REG_USE_CHAIN (reg);
+ ref != NULL;
+ ref = DF_REF_NEXT_REG (ref))
+ {
+ if (DF_REF_IS_ARTIFICIAL (ref))
+ continue;
+
+ rtx_insn *insn = DF_REF_INSN (ref);
+
+ if (!NONJUMP_INSN_P (insn))
+ continue;
+
+ rtx set = single_set (insn);
+ if (set)
+ ix86_find_all_reg_use_1 (set, stack_slot_access, worklist);
+
+ rtx pat = PATTERN (insn);
+ if (GET_CODE (pat) != PARALLEL)
+ continue;
+
+ for (int i = 0; i < XVECLEN (pat, 0); i++)
+ {
+ rtx exp = XVECEXP (pat, 0, i);
+ switch (GET_CODE (exp))
+ {
+ case ASM_OPERANDS:
+ case CLOBBER:
+ case PREFETCH:
+ case USE:
+ break;
+ case UNSPEC:
+ case UNSPEC_VOLATILE:
+ for (int j = XVECLEN (exp, 0) - 1; j >= 0; j--)
+ {
+ rtx x = XVECEXP (exp, 0, j);
+ if (GET_CODE (x) == SET)
+ ix86_find_all_reg_use_1 (x, stack_slot_access,
+ worklist);
+ }
+ break;
+ case SET:
+ ix86_find_all_reg_use_1 (exp, stack_slot_access,
+ worklist);
+ break;
+ default:
+ gcc_unreachable ();
+ break;
+ }
+ }
+ }
+}
+
/* Set stack_frame_required to false if stack frame isn't required.
Update STACK_ALIGNMENT to the largest alignment, in bits, of stack
slot used if stack frame is required and CHECK_STACK_SLOT is true. */
@@ -8484,10 +8585,6 @@ ix86_find_max_used_stack_alignment (unsigned int
&stack_alignment,
add_to_hard_reg_set (&set_up_by_prologue, Pmode,
HARD_FRAME_POINTER_REGNUM);
- /* The preferred stack alignment is the minimum stack alignment. */
- if (stack_alignment > crtl->preferred_stack_boundary)
- stack_alignment = crtl->preferred_stack_boundary;
-
bool require_stack_frame = false;
FOR_EACH_BB_FN (bb, cfun)
@@ -8499,27 +8596,65 @@ ix86_find_max_used_stack_alignment (unsigned int
&stack_alignment,
set_up_by_prologue))
{
require_stack_frame = true;
-
- if (check_stack_slot)
- {
- /* Find the maximum stack alignment. */
- subrtx_iterator::array_type array;
- FOR_EACH_SUBRTX (iter, array, PATTERN (insn), ALL)
- if (MEM_P (*iter)
- && (reg_mentioned_p (stack_pointer_rtx,
- *iter)
- || reg_mentioned_p (frame_pointer_rtx,
- *iter)))
- {
- unsigned int alignment = MEM_ALIGN (*iter);
- if (alignment > stack_alignment)
- stack_alignment = alignment;
- }
- }
+ break;
}
}
cfun->machine->stack_frame_required = require_stack_frame;
+
+ /* Stop if we don't need to check stack slot. */
+ if (!check_stack_slot)
+ return;
+
+ /* The preferred stack alignment is the minimum stack alignment. */
+ if (stack_alignment > crtl->preferred_stack_boundary)
+ stack_alignment = crtl->preferred_stack_boundary;
+
+ HARD_REG_SET stack_slot_access;
+ CLEAR_HARD_REG_SET (stack_slot_access);
+
+ /* Stack slot can be accessed by stack pointer, frame pointer or
+ registers defined by stack pointer or frame pointer. */
+ auto_bitmap worklist;
+
+ add_to_hard_reg_set (&stack_slot_access, Pmode,
+ STACK_POINTER_REGNUM);
+ bitmap_set_bit (worklist, STACK_POINTER_REGNUM);
+
+ if (frame_pointer_needed)
+ {
+ add_to_hard_reg_set (&stack_slot_access, Pmode,
+ HARD_FRAME_POINTER_REGNUM);
+ bitmap_set_bit (worklist, HARD_FRAME_POINTER_REGNUM);
+ }
+
+ unsigned int reg;
+
+ do
+ {
+ reg = bitmap_clear_first_set_bit (worklist);
+ ix86_find_all_reg_use (stack_slot_access, reg, worklist);
+ }
+ while (!bitmap_empty_p (worklist));
+
+ hard_reg_set_iterator hrsi;
+
+ EXECUTE_IF_SET_IN_HARD_REG_SET (stack_slot_access, 0, reg, hrsi)
+ for (df_ref ref = DF_REG_USE_CHAIN (reg);
+ ref != NULL;
+ ref = DF_REF_NEXT_REG (ref))
+ {
+ if (DF_REF_IS_ARTIFICIAL (ref))
+ continue;
+
+ rtx_insn *insn = DF_REF_INSN (ref);
+
+ if (!NONJUMP_INSN_P (insn))
+ continue;
+
+ note_stores (insn, ix86_update_stack_alignment,
+ &stack_alignment);
+ }
}
/* Finalize stack_realign_needed and frame_pointer_needed flags, which
diff --git a/gcc/testsuite/g++.target/i386/pr109780-1.C
b/gcc/testsuite/g++.target/i386/pr109780-1.C
new file mode 100644
index 000000000000..7e3eabdec947
--- /dev/null
+++ b/gcc/testsuite/g++.target/i386/pr109780-1.C
@@ -0,0 +1,72 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target c++17 } */
+/* { dg-options "-O2 -mavx2 -mtune=haswell" } */
+
+template <typename _Tp> struct remove_reference {
+ using type = __remove_reference(_Tp);
+};
+template <typename T> struct MaybeStorageBase {
+ T val;
+ struct Union {
+ ~Union();
+ } mStorage;
+};
+template <typename T> struct MaybeStorage : MaybeStorageBase<T> {
+ char mIsSome;
+};
+template <typename T, typename U = typename remove_reference<T>::type>
+constexpr MaybeStorage<U> Some(T &&);
+template <typename T, typename U> constexpr MaybeStorage<U> Some(T &&aValue) {
+ return {aValue};
+}
+template <class> struct Span {
+ int operator[](long idx) {
+ int *__trans_tmp_4;
+ if (__builtin_expect(idx, 0))
+ *(int *)__null = false;
+ __trans_tmp_4 = storage_.data();
+ return __trans_tmp_4[idx];
+ }
+ struct {
+ int *data() { return data_; }
+ int *data_;
+ } storage_;
+};
+struct Variant {
+ template <typename RefT> Variant(RefT) {}
+};
+long from_i, from___trans_tmp_9;
+namespace js::intl {
+struct DecimalNumber {
+ Variant string_;
+ unsigned long significandStart_;
+ unsigned long significandEnd_;
+ bool zero_ = false;
+ bool negative_;
+ template <typename CharT> DecimalNumber(CharT string) : string_(string) {}
+ template <typename CharT>
+ static MaybeStorage<DecimalNumber> from(Span<const CharT>);
+ void from();
+};
+} // namespace js::intl
+void js::intl::DecimalNumber::from() {
+ Span<const char16_t> __trans_tmp_3;
+ from(__trans_tmp_3);
+}
+template <typename CharT>
+MaybeStorage<js::intl::DecimalNumber>
+js::intl::DecimalNumber::from(Span<const CharT> chars) {
+ DecimalNumber number(chars);
+ if (auto ch = chars[from_i]) {
+ from_i++;
+ number.negative_ = ch == '-';
+ }
+ while (from___trans_tmp_9 && chars[from_i])
+ ;
+ if (chars[from_i])
+ while (chars[from_i - 1])
+ number.zero_ = true;
+ return Some(number);
+}
+
+/* { dg-final { scan-assembler-not "and\[lq\]?\[^\\n\]*-32,\[^\\n\]*sp" } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr109093-1.c
b/gcc/testsuite/gcc.target/i386/pr109093-1.c
new file mode 100644
index 000000000000..58a7b006c8ae
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr109093-1.c
@@ -0,0 +1,33 @@
+/* { dg-do run { target avx2_runtime } } */
+/* { dg-options "-O2 -mavx2 -mtune=znver1 -ftrivial-auto-var-init=zero
-fno-stack-protector" } */
+
+int a, b, c, d;
+char e, f = 1;
+short g, h, i;
+
+__attribute__ ((weak))
+void
+run (void)
+{
+ short j;
+
+ for (; g >= 0; --g)
+ {
+ int *k[10];
+
+ for (d = 0; d < 10; d++)
+ k[d] = &b;
+
+ c = *k[1];
+
+ for (; a;)
+ j = i - c / f || (e ^= h);
+ }
+}
+
+int
+main (void)
+{
+ run ();
+ return 0;
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr109780-1.c
b/gcc/testsuite/gcc.target/i386/pr109780-1.c
new file mode 100644
index 000000000000..6b06947f2a54
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr109780-1.c
@@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -march=skylake" } */
+
+char perm[64];
+
+void
+__attribute__((noipa))
+foo (int n)
+{
+ for (int i = 0; i < n; ++i)
+ perm[i] = i;
+}
+
+/* { dg-final { scan-assembler-not "and\[lq\]?\[^\\n\]*-32,\[^\\n\]*sp" } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr109780-2.c
b/gcc/testsuite/gcc.target/i386/pr109780-2.c
new file mode 100644
index 000000000000..152da06c6ad1
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr109780-2.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -march=skylake" } */
+
+#define N 9
+
+void
+f (double x, double y, double *res)
+{
+ y = -y;
+ for (int i = 0; i < N; ++i)
+ {
+ double tmp = y;
+ y = x;
+ x = tmp;
+ res[i] = i;
+ }
+ res[N] = y * y;
+ res[N + 1] = x;
+}
+
+/* { dg-final { scan-assembler-not "and\[lq\]?\[^\\n\]*-32,\[^\\n\]*sp" } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr109780-3.c
b/gcc/testsuite/gcc.target/i386/pr109780-3.c
new file mode 100644
index 000000000000..a3a770a80e39
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr109780-3.c
@@ -0,0 +1,46 @@
+/* { dg-do run { target avx2_runtime } } */
+/* { dg-options "-O2 -mavx2 -mtune=znver1 -fno-stack-protector
-fno-stack-clash-protection" } */
+
+char a;
+static int b, c, f;
+char *d = &a;
+static char *e = &a;
+
+__attribute__ ((weak))
+void
+g (int h, int i)
+{
+ int j = 1;
+ for (; c != -3; c = c - 1)
+ {
+ int k[10];
+ f = 0;
+ for (; f < 10; f++)
+ k[f] = 0;
+ *d = k[1];
+ if (i < *d)
+ {
+ *e = h;
+ for (; j < 9; j++)
+ {
+ b = 1;
+ for (; b < 7; b++)
+ ;
+ }
+ }
+ }
+}
+
+__attribute__ ((weak))
+void
+run (void)
+{
+ g (1, 1);
+}
+
+int
+main (void)
+{
+ run ();
+ return 0;
+}
