143 lines
4.7 KiB
Diff
143 lines
4.7 KiB
Diff
2019-04-15 Segher Boessenkool <segher@kernel.crashing.org>
|
|
|
|
PR rtl-optimization/89794
|
|
* combine.c (count_auto_inc): New function.
|
|
(try_combine): Count how many auto_inc expressions there were in the
|
|
original instructions. Ensure we have the same number in the new
|
|
instructions. Remove the code that tried to ensure auto_inc side
|
|
effects on i1 and i0 are not lost.
|
|
|
|
* gcc.dg/torture/pr89794.c: New testcase.
|
|
|
|
--- gcc/combine.c (revision 270367)
|
|
+++ gcc/combine.c (revision 270368)
|
|
@@ -2641,6 +2641,16 @@ is_just_move (rtx x)
|
|
return (GET_CODE (x) == SET && general_operand (SET_SRC (x), VOIDmode));
|
|
}
|
|
|
|
+/* Callback function to count autoincs. */
|
|
+
|
|
+static int
|
|
+count_auto_inc (rtx, rtx, rtx, rtx, rtx, void *arg)
|
|
+{
|
|
+ (*((int *) arg))++;
|
|
+
|
|
+ return 0;
|
|
+}
|
|
+
|
|
/* Try to combine the insns I0, I1 and I2 into I3.
|
|
Here I0, I1 and I2 appear earlier than I3.
|
|
I0 and I1 can be zero; then we combine just I2 into I3, or I1 and I2 into
|
|
@@ -2706,6 +2716,7 @@ try_combine (rtx_insn *i3, rtx_insn *i2,
|
|
int split_i2i3 = 0;
|
|
int changed_i3_dest = 0;
|
|
bool i2_was_move = false, i3_was_move = false;
|
|
+ int n_auto_inc = 0;
|
|
|
|
int maxreg;
|
|
rtx_insn *temp_insn;
|
|
@@ -3210,6 +3221,16 @@ try_combine (rtx_insn *i3, rtx_insn *i2,
|
|
return 0;
|
|
}
|
|
|
|
+ /* Count how many auto_inc expressions there were in the original insns;
|
|
+ we need to have the same number in the resulting patterns. */
|
|
+
|
|
+ if (i0)
|
|
+ for_each_inc_dec (PATTERN (i0), count_auto_inc, &n_auto_inc);
|
|
+ if (i1)
|
|
+ for_each_inc_dec (PATTERN (i1), count_auto_inc, &n_auto_inc);
|
|
+ for_each_inc_dec (PATTERN (i2), count_auto_inc, &n_auto_inc);
|
|
+ for_each_inc_dec (PATTERN (i3), count_auto_inc, &n_auto_inc);
|
|
+
|
|
/* If the set in I2 needs to be kept around, we must make a copy of
|
|
PATTERN (I2), so that when we substitute I1SRC for I1DEST in
|
|
PATTERN (I2), we are only substituting for the original I1DEST, not into
|
|
@@ -3411,18 +3432,11 @@ try_combine (rtx_insn *i3, rtx_insn *i2,
|
|
|
|
if (i1 && GET_CODE (newpat) != CLOBBER)
|
|
{
|
|
- /* Check that an autoincrement side-effect on I1 has not been lost.
|
|
- This happens if I1DEST is mentioned in I2 and dies there, and
|
|
- has disappeared from the new pattern. */
|
|
- if ((FIND_REG_INC_NOTE (i1, NULL_RTX) != 0
|
|
- && i1_feeds_i2_n
|
|
- && dead_or_set_p (i2, i1dest)
|
|
- && !reg_overlap_mentioned_p (i1dest, newpat))
|
|
- /* Before we can do this substitution, we must redo the test done
|
|
- above (see detailed comments there) that ensures I1DEST isn't
|
|
- mentioned in any SETs in NEWPAT that are field assignments. */
|
|
- || !combinable_i3pat (NULL, &newpat, i1dest, NULL_RTX, NULL_RTX,
|
|
- 0, 0, 0))
|
|
+ /* Before we can do this substitution, we must redo the test done
|
|
+ above (see detailed comments there) that ensures I1DEST isn't
|
|
+ mentioned in any SETs in NEWPAT that are field assignments. */
|
|
+ if (!combinable_i3pat (NULL, &newpat, i1dest, NULL_RTX, NULL_RTX,
|
|
+ 0, 0, 0))
|
|
{
|
|
undo_all ();
|
|
return 0;
|
|
@@ -3452,12 +3466,8 @@ try_combine (rtx_insn *i3, rtx_insn *i2,
|
|
|
|
if (i0 && GET_CODE (newpat) != CLOBBER)
|
|
{
|
|
- if ((FIND_REG_INC_NOTE (i0, NULL_RTX) != 0
|
|
- && ((i0_feeds_i2_n && dead_or_set_p (i2, i0dest))
|
|
- || (i0_feeds_i1_n && dead_or_set_p (i1, i0dest)))
|
|
- && !reg_overlap_mentioned_p (i0dest, newpat))
|
|
- || !combinable_i3pat (NULL, &newpat, i0dest, NULL_RTX, NULL_RTX,
|
|
- 0, 0, 0))
|
|
+ if (!combinable_i3pat (NULL, &newpat, i0dest, NULL_RTX, NULL_RTX,
|
|
+ 0, 0, 0))
|
|
{
|
|
undo_all ();
|
|
return 0;
|
|
@@ -3478,6 +3488,20 @@ try_combine (rtx_insn *i3, rtx_insn *i2,
|
|
substed_i0 = 1;
|
|
}
|
|
|
|
+ if (n_auto_inc)
|
|
+ {
|
|
+ int new_n_auto_inc = 0;
|
|
+ for_each_inc_dec (newpat, count_auto_inc, &new_n_auto_inc);
|
|
+
|
|
+ if (n_auto_inc != new_n_auto_inc)
|
|
+ {
|
|
+ if (dump_file && (dump_flags & TDF_DETAILS))
|
|
+ fprintf (dump_file, "Number of auto_inc expressions changed\n");
|
|
+ undo_all ();
|
|
+ return 0;
|
|
+ }
|
|
+ }
|
|
+
|
|
/* Fail if an autoincrement side-effect has been duplicated. Be careful
|
|
to count all the ways that I2SRC and I1SRC can be used. */
|
|
if ((FIND_REG_INC_NOTE (i2, NULL_RTX) != 0
|
|
--- gcc/testsuite/gcc.dg/torture/pr89794.c (nonexistent)
|
|
+++ gcc/testsuite/gcc.dg/torture/pr89794.c (revision 270368)
|
|
@@ -0,0 +1,24 @@
|
|
+/* { dg-do run } */
|
|
+
|
|
+typedef unsigned short u16;
|
|
+typedef unsigned int u32;
|
|
+typedef unsigned long long u64;
|
|
+
|
|
+u32 a, b, c, d;
|
|
+
|
|
+u32 foo (u32 f, u32 g, u32 g2, u32 g3, u16 h, u16 i)
|
|
+{
|
|
+ (void)g, (void)g2, (void)g3, (void)h;
|
|
+ d = __builtin_bswap64 (i);
|
|
+ __builtin_sub_overflow (0, d, &b);
|
|
+ __builtin_memset (&i, c, 2);
|
|
+ a = 0;
|
|
+ return b + f + i + c;
|
|
+}
|
|
+
|
|
+int main (void)
|
|
+{
|
|
+ u32 x = foo (0, 0, 0, 0, 0, 0);
|
|
+ asm ("" :: "r" (x));
|
|
+ return 0;
|
|
+}
|