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* [gcc r13-5223] forwprop: Fix up rotate pattern matching [PR106523]
@ 2023-01-17 11:19 Jakub Jelinek
0 siblings, 0 replies; only message in thread
From: Jakub Jelinek @ 2023-01-17 11:19 UTC (permalink / raw)
To: gcc-cvs
https://gcc.gnu.org/g:001121e8921d5d1a439ce0e64ab04c5959b0bfd8
commit r13-5223-g001121e8921d5d1a439ce0e64ab04c5959b0bfd8
Author: Jakub Jelinek <jakub@redhat.com>
Date: Tue Jan 17 12:14:25 2023 +0100
forwprop: Fix up rotate pattern matching [PR106523]
The comment above simplify_rotate roughly describes what patterns
are matched into what:
We are looking for X with unsigned type T with bitsize B, OP being
+, | or ^, some type T2 wider than T. For:
(X << CNT1) OP (X >> CNT2) iff CNT1 + CNT2 == B
((T) ((T2) X << CNT1)) OP ((T) ((T2) X >> CNT2)) iff CNT1 + CNT2 == B
transform these into:
X r<< CNT1
Or for:
(X << Y) OP (X >> (B - Y))
(X << (int) Y) OP (X >> (int) (B - Y))
((T) ((T2) X << Y)) OP ((T) ((T2) X >> (B - Y)))
((T) ((T2) X << (int) Y)) OP ((T) ((T2) X >> (int) (B - Y)))
(X << Y) | (X >> ((-Y) & (B - 1)))
(X << (int) Y) | (X >> (int) ((-Y) & (B - 1)))
((T) ((T2) X << Y)) | ((T) ((T2) X >> ((-Y) & (B - 1))))
((T) ((T2) X << (int) Y)) | ((T) ((T2) X >> (int) ((-Y) & (B - 1))))
transform these into (last 2 only if ranger can prove Y < B):
X r<< Y
Or for:
(X << (Y & (B - 1))) | (X >> ((-Y) & (B - 1)))
(X << (int) (Y & (B - 1))) | (X >> (int) ((-Y) & (B - 1)))
((T) ((T2) X << (Y & (B - 1)))) | ((T) ((T2) X >> ((-Y) & (B - 1))))
((T) ((T2) X << (int) (Y & (B - 1)))) \
| ((T) ((T2) X >> (int) ((-Y) & (B - 1))))
transform these into:
X r<< (Y & (B - 1))
The following testcase shows that 2 of these are problematic.
If T2 is wider than T, then the 2 which yse (-Y) & (B - 1) on one
of the shift counts but Y on the can do something different from
rotate. E.g.:
__attribute__((noipa)) unsigned char
f7 (unsigned char x, unsigned int y)
{
unsigned int t = x;
return (t << y) | (t >> ((-y) & 7));
}
if y is [0, 7], then it is a normal rotate, and if y is in [32, ~0U]
then it is UB, but for y in [9, 31] the left shift in this case
will never leave any bits in the result, while in a rotate they are
left there. Say for y 5 and x 0xaa the expression gives
0x55 which is the same thing as rotate, while for y 19 and x 0xaa
0x5, which is different.
Now, I believe the
((T) ((T2) X << Y)) OP ((T) ((T2) X >> (B - Y)))
((T) ((T2) X << (int) Y)) OP ((T) ((T2) X >> (int) (B - Y)))
forms are ok, because B - Y still needs to be a valid shift count,
and if Y > B then B - Y should be either negative or very large
positive (for unsigned types).
And similarly the last 2 cases above which use & (B - 1) on both
shift operands are definitely ok.
The following patch disables the
((T) ((T2) X << Y)) | ((T) ((T2) X >> ((-Y) & (B - 1))))
((T) ((T2) X << (int) Y)) | ((T) ((T2) X >> (int) ((-Y) & (B - 1))))
unless ranger says Y is not in [B, B2 - 1] range.
And, looking at it again this morning, actually the Y equal to B
case is still fine, if Y is equal to 0, then it is
(T) (((T2) X << 0) | ((T2) X >> 0))
and so X, for Y == B it is
(T) (((T2) X << B) | ((T2) X >> 0))
which is the same as
(T) (0 | ((T2) X >> 0))
which is also X. So instead of the [B, B2 - 1] range we could use
[B + 1, B2 - 1]. And, if we wanted to go further, even multiplies
of B are ok if they are smaller than B2, so we could construct a detailed
int_range_max if we wanted.
2023-01-17 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/106523
* tree-ssa-forwprop.cc (simplify_rotate): For the
patterns with (-Y) & (B - 1) in one operand's shift
count and Y in another, if T2 has wider precision than T,
punt if Y could have a value in [B, B2 - 1] range.
* c-c++-common/rotate-2.c (f5, f6, f7, f8, f13, f14, f15, f16,
f37, f38, f39, f40, f45, f46, f47, f48): Add assertions using
__builtin_unreachable about shift count.
* c-c++-common/rotate-2b.c: New test.
* c-c++-common/rotate-4.c (f5, f6, f7, f8, f13, f14, f15, f16,
f37, f38, f39, f40, f45, f46, f47, f48): Add assertions using
__builtin_unreachable about shift count.
* c-c++-common/rotate-4b.c: New test.
* gcc.c-torture/execute/pr106523.c: New test.
Diff:
---
gcc/testsuite/c-c++-common/rotate-2.c | 32 ++++++++
gcc/testsuite/c-c++-common/rotate-2b.c | 100 +++++++++++++++++++++++++
gcc/testsuite/c-c++-common/rotate-4.c | 32 ++++++++
gcc/testsuite/c-c++-common/rotate-4b.c | 100 +++++++++++++++++++++++++
gcc/testsuite/gcc.c-torture/execute/pr106523.c | 22 ++++++
gcc/tree-ssa-forwprop.cc | 53 ++++++++++++-
6 files changed, 335 insertions(+), 4 deletions(-)
diff --git a/gcc/testsuite/c-c++-common/rotate-2.c b/gcc/testsuite/c-c++-common/rotate-2.c
index c8359cd2ae0..544a7ca298f 100644
--- a/gcc/testsuite/c-c++-common/rotate-2.c
+++ b/gcc/testsuite/c-c++-common/rotate-2.c
@@ -32,24 +32,32 @@ f4 (unsigned int x, int y __attribute__((unused)))
unsigned short int
f5 (unsigned short int x, unsigned int y)
{
+ if (y >= __CHAR_BIT__ * __SIZEOF_SHORT__)
+ __builtin_unreachable ();
return (x << y) | (x >> ((-y) & (__CHAR_BIT__ * __SIZEOF_SHORT__ - 1)));
}
unsigned short int
f6 (unsigned short int x, unsigned long int y)
{
+ if (y >= __CHAR_BIT__ * __SIZEOF_SHORT__)
+ __builtin_unreachable ();
return (x << y) | (x >> ((-y) & (__CHAR_BIT__ * __SIZEOF_SHORT__ - 1)));
}
unsigned char
f7 (unsigned char x, unsigned int y)
{
+ if (y >= __CHAR_BIT__)
+ __builtin_unreachable ();
return (x << y) | (x >> ((-y) & (__CHAR_BIT__ - 1)));
}
unsigned char
f8 (unsigned char x, unsigned long int y)
{
+ if (y >= __CHAR_BIT__)
+ __builtin_unreachable ();
return (x << y) | (x >> ((-y) & (__CHAR_BIT__ - 1)));
}
@@ -80,24 +88,32 @@ f12 (unsigned int x, int y __attribute__((unused)))
unsigned short int
f13 (unsigned short int x, unsigned int y)
{
+ if (y >= __CHAR_BIT__ * __SIZEOF_SHORT__)
+ __builtin_unreachable ();
return (x << y) | (x >> ((-y) & (__CHAR_BIT__ * sizeof (unsigned short) - 1)));
}
unsigned short int
f14 (unsigned short int x, unsigned long int y)
{
+ if (y >= __CHAR_BIT__ * __SIZEOF_SHORT__)
+ __builtin_unreachable ();
return (x << y) | (x >> ((-y) & (__CHAR_BIT__ * sizeof (unsigned short) - 1)));
}
unsigned char
f15 (unsigned char x, unsigned int y)
{
+ if (y >= __CHAR_BIT__)
+ __builtin_unreachable ();
return (x << y) | (x >> ((-y) & (__CHAR_BIT__ * sizeof (unsigned char) - 1)));
}
unsigned char
f16 (unsigned char x, unsigned long int y)
{
+ if (y >= __CHAR_BIT__)
+ __builtin_unreachable ();
return (x << y) | (x >> ((-y) & (__CHAR_BIT__ * sizeof (unsigned char) - 1)));
}
@@ -224,24 +240,32 @@ f36 (unsigned int x, int y __attribute__((unused)))
unsigned short int
f37 (unsigned short int x, unsigned int y)
{
+ if (y >= __CHAR_BIT__ * __SIZEOF_SHORT__)
+ __builtin_unreachable ();
return (x >> y) | (x << ((-y) & (__CHAR_BIT__ * __SIZEOF_SHORT__ - 1)));
}
unsigned short int
f38 (unsigned short int x, unsigned long int y)
{
+ if (y >= __CHAR_BIT__ * __SIZEOF_SHORT__)
+ __builtin_unreachable ();
return (x >> y) | (x << ((-y) & (__CHAR_BIT__ * __SIZEOF_SHORT__ - 1)));
}
unsigned char
f39 (unsigned char x, unsigned int y)
{
+ if (y >= __CHAR_BIT__)
+ __builtin_unreachable ();
return (x >> y) | (x << ((-y) & (__CHAR_BIT__ - 1)));
}
unsigned char
f40 (unsigned char x, unsigned long int y)
{
+ if (y >= __CHAR_BIT__)
+ __builtin_unreachable ();
return (x >> y) | (x << ((-y) & (__CHAR_BIT__ - 1)));
}
@@ -272,24 +296,32 @@ f44 (unsigned int x, int y __attribute__((unused)))
unsigned short int
f45 (unsigned short int x, unsigned int y)
{
+ if (y >= __CHAR_BIT__ * __SIZEOF_SHORT__)
+ __builtin_unreachable ();
return (x >> y) | (x << ((-y) & (__CHAR_BIT__ * sizeof (unsigned short) - 1)));
}
unsigned short int
f46 (unsigned short int x, unsigned long int y)
{
+ if (y >= __CHAR_BIT__ * __SIZEOF_SHORT__)
+ __builtin_unreachable ();
return (x >> y) | (x << ((-y) & (__CHAR_BIT__ * sizeof (unsigned short) - 1)));
}
unsigned char
f47 (unsigned char x, unsigned int y)
{
+ if (y >= __CHAR_BIT__)
+ __builtin_unreachable ();
return (x >> y) | (x << ((-y) & (__CHAR_BIT__ * sizeof (unsigned char) - 1)));
}
unsigned char
f48 (unsigned char x, unsigned long int y)
{
+ if (y >= __CHAR_BIT__)
+ __builtin_unreachable ();
return (x >> y) | (x << ((-y) & (__CHAR_BIT__ * sizeof (unsigned char) - 1)));
}
diff --git a/gcc/testsuite/c-c++-common/rotate-2b.c b/gcc/testsuite/c-c++-common/rotate-2b.c
new file mode 100644
index 00000000000..2a6bf909ae6
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/rotate-2b.c
@@ -0,0 +1,100 @@
+/* Check rotate pattern detection. */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fno-ipa-icf -fdump-tree-optimized" } */
+/* { dg-final { scan-tree-dump-not "r\[<>]\[<>]" "optimized" } } */
+
+unsigned short int
+f5 (unsigned short int x, unsigned int y)
+{
+ return (x << y) | (x >> ((-y) & (__CHAR_BIT__ * __SIZEOF_SHORT__ - 1)));
+}
+
+unsigned short int
+f6 (unsigned short int x, unsigned long int y)
+{
+ return (x << y) | (x >> ((-y) & (__CHAR_BIT__ * __SIZEOF_SHORT__ - 1)));
+}
+
+unsigned char
+f7 (unsigned char x, unsigned int y)
+{
+ return (x << y) | (x >> ((-y) & (__CHAR_BIT__ - 1)));
+}
+
+unsigned char
+f8 (unsigned char x, unsigned long int y)
+{
+ return (x << y) | (x >> ((-y) & (__CHAR_BIT__ - 1)));
+}
+
+unsigned short int
+f13 (unsigned short int x, unsigned int y)
+{
+ return (x << y) | (x >> ((-y) & (__CHAR_BIT__ * sizeof (unsigned short) - 1)));
+}
+
+unsigned short int
+f14 (unsigned short int x, unsigned long int y)
+{
+ return (x << y) | (x >> ((-y) & (__CHAR_BIT__ * sizeof (unsigned short) - 1)));
+}
+
+unsigned char
+f15 (unsigned char x, unsigned int y)
+{
+ return (x << y) | (x >> ((-y) & (__CHAR_BIT__ * sizeof (unsigned char) - 1)));
+}
+
+unsigned char
+f16 (unsigned char x, unsigned long int y)
+{
+ return (x << y) | (x >> ((-y) & (__CHAR_BIT__ * sizeof (unsigned char) - 1)));
+}
+
+unsigned short int
+f37 (unsigned short int x, unsigned int y)
+{
+ return (x >> y) | (x << ((-y) & (__CHAR_BIT__ * __SIZEOF_SHORT__ - 1)));
+}
+
+unsigned short int
+f38 (unsigned short int x, unsigned long int y)
+{
+ return (x >> y) | (x << ((-y) & (__CHAR_BIT__ * __SIZEOF_SHORT__ - 1)));
+}
+
+unsigned char
+f39 (unsigned char x, unsigned int y)
+{
+ return (x >> y) | (x << ((-y) & (__CHAR_BIT__ - 1)));
+}
+
+unsigned char
+f40 (unsigned char x, unsigned long int y)
+{
+ return (x >> y) | (x << ((-y) & (__CHAR_BIT__ - 1)));
+}
+
+unsigned short int
+f45 (unsigned short int x, unsigned int y)
+{
+ return (x >> y) | (x << ((-y) & (__CHAR_BIT__ * sizeof (unsigned short) - 1)));
+}
+
+unsigned short int
+f46 (unsigned short int x, unsigned long int y)
+{
+ return (x >> y) | (x << ((-y) & (__CHAR_BIT__ * sizeof (unsigned short) - 1)));
+}
+
+unsigned char
+f47 (unsigned char x, unsigned int y)
+{
+ return (x >> y) | (x << ((-y) & (__CHAR_BIT__ * sizeof (unsigned char) - 1)));
+}
+
+unsigned char
+f48 (unsigned char x, unsigned long int y)
+{
+ return (x >> y) | (x << ((-y) & (__CHAR_BIT__ * sizeof (unsigned char) - 1)));
+}
diff --git a/gcc/testsuite/c-c++-common/rotate-4.c b/gcc/testsuite/c-c++-common/rotate-4.c
index 44fd1d0bb83..f85236239d8 100644
--- a/gcc/testsuite/c-c++-common/rotate-4.c
+++ b/gcc/testsuite/c-c++-common/rotate-4.c
@@ -32,24 +32,32 @@ f4 (unsigned int x, int y __attribute__((unused)))
unsigned short int
f5 (unsigned short int x, int y)
{
+ if (y >= __CHAR_BIT__ * __SIZEOF_SHORT__)
+ __builtin_unreachable ();
return (x << y) | (x >> ((-y) & (__CHAR_BIT__ * __SIZEOF_SHORT__ - 1)));
}
unsigned short int
f6 (unsigned short int x, long int y)
{
+ if (y >= 0UL + __CHAR_BIT__ * __SIZEOF_SHORT__)
+ __builtin_unreachable ();
return (x << y) | (x >> ((-y) & (__CHAR_BIT__ * __SIZEOF_SHORT__ - 1)));
}
unsigned char
f7 (unsigned char x, int y)
{
+ if (y >= __CHAR_BIT__)
+ __builtin_unreachable ();
return (x << y) | (x >> ((-y) & (__CHAR_BIT__ - 1)));
}
unsigned char
f8 (unsigned char x, long int y)
{
+ if (y >= 0UL + __CHAR_BIT__)
+ __builtin_unreachable ();
return (x << y) | (x >> ((-y) & (__CHAR_BIT__ - 1)));
}
@@ -80,24 +88,32 @@ f12 (unsigned int x, int y __attribute__((unused)))
unsigned short int
f13 (unsigned short int x, int y)
{
+ if (y >= __CHAR_BIT__ * __SIZEOF_SHORT__)
+ __builtin_unreachable ();
return (x << y) | (x >> ((-y) & (__CHAR_BIT__ * sizeof (unsigned short) - 1)));
}
unsigned short int
f14 (unsigned short int x, long int y)
{
+ if (y >= 0UL + __CHAR_BIT__ * __SIZEOF_SHORT__)
+ __builtin_unreachable ();
return (x << y) | (x >> ((-y) & (__CHAR_BIT__ * sizeof (unsigned short) - 1)));
}
unsigned char
f15 (unsigned char x, int y)
{
+ if (y >= __CHAR_BIT__)
+ __builtin_unreachable ();
return (x << y) | (x >> ((-y) & (__CHAR_BIT__ * sizeof (unsigned char) - 1)));
}
unsigned char
f16 (unsigned char x, long int y)
{
+ if (y >= 0UL + __CHAR_BIT__)
+ __builtin_unreachable ();
return (x << y) | (x >> ((-y) & (__CHAR_BIT__ * sizeof (unsigned char) - 1)));
}
@@ -224,24 +240,32 @@ f36 (unsigned int x, int y __attribute__((unused)))
unsigned short int
f37 (unsigned short int x, int y)
{
+ if (y >= __CHAR_BIT__ * __SIZEOF_SHORT__)
+ __builtin_unreachable ();
return (x >> y) | (x << ((-y) & (__CHAR_BIT__ * __SIZEOF_SHORT__ - 1)));
}
unsigned short int
f38 (unsigned short int x, long int y)
{
+ if (y >= 0UL + __CHAR_BIT__ * __SIZEOF_SHORT__)
+ __builtin_unreachable ();
return (x >> y) | (x << ((-y) & (__CHAR_BIT__ * __SIZEOF_SHORT__ - 1)));
}
unsigned char
f39 (unsigned char x, int y)
{
+ if (y >= __CHAR_BIT__)
+ __builtin_unreachable ();
return (x >> y) | (x << ((-y) & (__CHAR_BIT__ - 1)));
}
unsigned char
f40 (unsigned char x, long int y)
{
+ if (y >= 0UL + __CHAR_BIT__)
+ __builtin_unreachable ();
return (x >> y) | (x << ((-y) & (__CHAR_BIT__ - 1)));
}
@@ -272,24 +296,32 @@ f44 (unsigned int x, int y __attribute__((unused)))
unsigned short int
f45 (unsigned short int x, int y)
{
+ if (y >= __CHAR_BIT__ * __SIZEOF_SHORT__)
+ __builtin_unreachable ();
return (x >> y) | (x << ((-y) & (__CHAR_BIT__ * sizeof (unsigned short) - 1)));
}
unsigned short int
f46 (unsigned short int x, long int y)
{
+ if (y >= 0UL + __CHAR_BIT__ * __SIZEOF_SHORT__)
+ __builtin_unreachable ();
return (x >> y) | (x << ((-y) & (__CHAR_BIT__ * sizeof (unsigned short) - 1)));
}
unsigned char
f47 (unsigned char x, int y)
{
+ if (y >= __CHAR_BIT__)
+ __builtin_unreachable ();
return (x >> y) | (x << ((-y) & (__CHAR_BIT__ * sizeof (unsigned char) - 1)));
}
unsigned char
f48 (unsigned char x, long int y)
{
+ if (y >= 0UL + __CHAR_BIT__)
+ __builtin_unreachable ();
return (x >> y) | (x << ((-y) & (__CHAR_BIT__ * sizeof (unsigned char) - 1)));
}
diff --git a/gcc/testsuite/c-c++-common/rotate-4b.c b/gcc/testsuite/c-c++-common/rotate-4b.c
new file mode 100644
index 00000000000..a3824754d63
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/rotate-4b.c
@@ -0,0 +1,100 @@
+/* Check rotate pattern detection. */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fno-ipa-icf -fdump-tree-optimized" } */
+/* { dg-final { scan-tree-dump-not "r\[<>]\[<>]" "optimized" } } */
+
+unsigned short int
+f5 (unsigned short int x, int y)
+{
+ return (x << y) | (x >> ((-y) & (__CHAR_BIT__ * __SIZEOF_SHORT__ - 1)));
+}
+
+unsigned short int
+f6 (unsigned short int x, long int y)
+{
+ return (x << y) | (x >> ((-y) & (__CHAR_BIT__ * __SIZEOF_SHORT__ - 1)));
+}
+
+unsigned char
+f7 (unsigned char x, int y)
+{
+ return (x << y) | (x >> ((-y) & (__CHAR_BIT__ - 1)));
+}
+
+unsigned char
+f8 (unsigned char x, long int y)
+{
+ return (x << y) | (x >> ((-y) & (__CHAR_BIT__ - 1)));
+}
+
+unsigned short int
+f13 (unsigned short int x, int y)
+{
+ return (x << y) | (x >> ((-y) & (__CHAR_BIT__ * sizeof (unsigned short) - 1)));
+}
+
+unsigned short int
+f14 (unsigned short int x, long int y)
+{
+ return (x << y) | (x >> ((-y) & (__CHAR_BIT__ * sizeof (unsigned short) - 1)));
+}
+
+unsigned char
+f15 (unsigned char x, int y)
+{
+ return (x << y) | (x >> ((-y) & (__CHAR_BIT__ * sizeof (unsigned char) - 1)));
+}
+
+unsigned char
+f16 (unsigned char x, long int y)
+{
+ return (x << y) | (x >> ((-y) & (__CHAR_BIT__ * sizeof (unsigned char) - 1)));
+}
+
+unsigned short int
+f37 (unsigned short int x, int y)
+{
+ return (x >> y) | (x << ((-y) & (__CHAR_BIT__ * __SIZEOF_SHORT__ - 1)));
+}
+
+unsigned short int
+f38 (unsigned short int x, long int y)
+{
+ return (x >> y) | (x << ((-y) & (__CHAR_BIT__ * __SIZEOF_SHORT__ - 1)));
+}
+
+unsigned char
+f39 (unsigned char x, int y)
+{
+ return (x >> y) | (x << ((-y) & (__CHAR_BIT__ - 1)));
+}
+
+unsigned char
+f40 (unsigned char x, long int y)
+{
+ return (x >> y) | (x << ((-y) & (__CHAR_BIT__ - 1)));
+}
+
+unsigned short int
+f45 (unsigned short int x, int y)
+{
+ return (x >> y) | (x << ((-y) & (__CHAR_BIT__ * sizeof (unsigned short) - 1)));
+}
+
+unsigned short int
+f46 (unsigned short int x, long int y)
+{
+ return (x >> y) | (x << ((-y) & (__CHAR_BIT__ * sizeof (unsigned short) - 1)));
+}
+
+unsigned char
+f47 (unsigned char x, int y)
+{
+ return (x >> y) | (x << ((-y) & (__CHAR_BIT__ * sizeof (unsigned char) - 1)));
+}
+
+unsigned char
+f48 (unsigned char x, long int y)
+{
+ return (x >> y) | (x << ((-y) & (__CHAR_BIT__ * sizeof (unsigned char) - 1)));
+}
diff --git a/gcc/testsuite/gcc.c-torture/execute/pr106523.c b/gcc/testsuite/gcc.c-torture/execute/pr106523.c
new file mode 100644
index 00000000000..abd78f59ce3
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr106523.c
@@ -0,0 +1,22 @@
+/* PR tree-optimization/106523 */
+
+__attribute__((noipa)) unsigned char
+f7 (unsigned char x, unsigned int y)
+{
+ unsigned int t = x;
+ return (t << y) | (t >> ((-y) & 7));
+}
+
+int
+main ()
+{
+ if (__CHAR_BIT__ != 8 || __SIZEOF_INT__ != 4)
+ return 0;
+
+ volatile unsigned char x = 152;
+ volatile unsigned int y = 19;
+ if (f7 (x, y) != 4)
+ __builtin_abort ();
+
+ return 0;
+}
diff --git a/gcc/tree-ssa-forwprop.cc b/gcc/tree-ssa-forwprop.cc
index 0a7e95683ce..458d9c8e483 100644
--- a/gcc/tree-ssa-forwprop.cc
+++ b/gcc/tree-ssa-forwprop.cc
@@ -1837,7 +1837,7 @@ defcodefor_name (tree name, enum tree_code *code, tree *arg1, tree *arg2)
((T) ((T2) X << Y)) | ((T) ((T2) X >> ((-Y) & (B - 1))))
((T) ((T2) X << (int) Y)) | ((T) ((T2) X >> (int) ((-Y) & (B - 1))))
- transform these into:
+ transform these into (last 2 only if ranger can prove Y < B):
X r<< Y
Or for:
@@ -1866,6 +1866,8 @@ simplify_rotate (gimple_stmt_iterator *gsi)
int i;
bool swapped_p = false;
gimple *g;
+ gimple *def_arg_stmt[2] = { NULL, NULL };
+ int wider_prec = 0;
arg[0] = gimple_assign_rhs1 (stmt);
arg[1] = gimple_assign_rhs2 (stmt);
@@ -1878,7 +1880,11 @@ simplify_rotate (gimple_stmt_iterator *gsi)
return false;
for (i = 0; i < 2; i++)
- defcodefor_name (arg[i], &def_code[i], &def_arg1[i], &def_arg2[i]);
+ {
+ defcodefor_name (arg[i], &def_code[i], &def_arg1[i], &def_arg2[i]);
+ if (TREE_CODE (arg[i]) == SSA_NAME)
+ def_arg_stmt[i] = SSA_NAME_DEF_STMT (arg[i]);
+ }
/* Look through narrowing (or same precision) conversions. */
if (CONVERT_EXPR_CODE_P (def_code[0])
@@ -1891,10 +1897,13 @@ simplify_rotate (gimple_stmt_iterator *gsi)
&& has_single_use (arg[0])
&& has_single_use (arg[1]))
{
+ wider_prec = TYPE_PRECISION (TREE_TYPE (def_arg1[0]));
for (i = 0; i < 2; i++)
{
arg[i] = def_arg1[i];
defcodefor_name (arg[i], &def_code[i], &def_arg1[i], &def_arg2[i]);
+ if (TREE_CODE (arg[i]) == SSA_NAME)
+ def_arg_stmt[i] = SSA_NAME_DEF_STMT (arg[i]);
}
}
else
@@ -1910,6 +1919,8 @@ simplify_rotate (gimple_stmt_iterator *gsi)
{
arg[i] = def_arg1[i];
defcodefor_name (arg[i], &def_code[i], &def_arg1[i], &def_arg2[i]);
+ if (TREE_CODE (arg[i]) == SSA_NAME)
+ def_arg_stmt[i] = SSA_NAME_DEF_STMT (arg[i]);
}
}
@@ -1983,6 +1994,9 @@ simplify_rotate (gimple_stmt_iterator *gsi)
{
tree cdef_arg1[2], cdef_arg2[2], def_arg2_alt[2];
enum tree_code cdef_code[2];
+ gimple *def_arg_alt_stmt[2] = { NULL, NULL };
+ bool check_range = false;
+ gimple *check_range_stmt = NULL;
/* Look through conversion of the shift count argument.
The C/C++ FE cast any shift count argument to integer_type_node.
The only problem might be if the shift count type maximum value
@@ -1999,9 +2013,13 @@ simplify_rotate (gimple_stmt_iterator *gsi)
&& type_has_mode_precision_p (TREE_TYPE (cdef_arg1[i])))
{
def_arg2_alt[i] = cdef_arg1[i];
+ if (TREE_CODE (def_arg2[i]) == SSA_NAME)
+ def_arg_alt_stmt[i] = SSA_NAME_DEF_STMT (def_arg2[i]);
defcodefor_name (def_arg2_alt[i], &cdef_code[i],
&cdef_arg1[i], &cdef_arg2[i]);
}
+ else
+ def_arg_alt_stmt[i] = def_arg_stmt[i];
}
for (i = 0; i < 2; i++)
/* Check for one shift count being Y and the other B - Y,
@@ -2024,7 +2042,7 @@ simplify_rotate (gimple_stmt_iterator *gsi)
if (CONVERT_EXPR_CODE_P (code)
&& INTEGRAL_TYPE_P (TREE_TYPE (tem))
&& TYPE_PRECISION (TREE_TYPE (tem))
- > floor_log2 (TYPE_PRECISION (rtype))
+ > floor_log2 (TYPE_PRECISION (rtype))
&& type_has_mode_precision_p (TREE_TYPE (tem))
&& (tem == def_arg2[1 - i]
|| tem == def_arg2_alt[1 - i]))
@@ -2053,7 +2071,7 @@ simplify_rotate (gimple_stmt_iterator *gsi)
if (CONVERT_EXPR_CODE_P (code)
&& INTEGRAL_TYPE_P (TREE_TYPE (tem))
&& TYPE_PRECISION (TREE_TYPE (tem))
- > floor_log2 (TYPE_PRECISION (rtype))
+ > floor_log2 (TYPE_PRECISION (rtype))
&& type_has_mode_precision_p (TREE_TYPE (tem)))
defcodefor_name (tem, &code, &tem, NULL);
@@ -2062,6 +2080,11 @@ simplify_rotate (gimple_stmt_iterator *gsi)
if (tem == def_arg2[1 - i] || tem == def_arg2_alt[1 - i])
{
rotcnt = tem;
+ check_range = true;
+ if (tem == def_arg2[1 - i])
+ check_range_stmt = def_arg_stmt[1 - i];
+ else
+ check_range_stmt = def_arg_alt_stmt[1 - i];
break;
}
tree tem2;
@@ -2076,6 +2099,11 @@ simplify_rotate (gimple_stmt_iterator *gsi)
|| tem2 == def_arg2_alt[1 - i])
{
rotcnt = tem2;
+ check_range = true;
+ if (tem2 == def_arg2[1 - i])
+ check_range_stmt = def_arg_stmt[1 - i];
+ else
+ check_range_stmt = def_arg_alt_stmt[1 - i];
break;
}
}
@@ -2111,6 +2139,23 @@ simplify_rotate (gimple_stmt_iterator *gsi)
}
}
}
+ if (check_range && wider_prec > TYPE_PRECISION (rtype))
+ {
+ if (TREE_CODE (rotcnt) != SSA_NAME)
+ return false;
+ int_range_max r;
+ if (!get_global_range_query ()->range_of_expr (r, rotcnt,
+ check_range_stmt))
+ return false;
+ int prec = TYPE_PRECISION (TREE_TYPE (rotcnt));
+ signop sign = TYPE_SIGN (TREE_TYPE (rotcnt));
+ wide_int min = wide_int::from (TYPE_PRECISION (rtype), prec, sign);
+ wide_int max = wide_int::from (wider_prec - 1, prec, sign);
+ int_range<2> r2 (TREE_TYPE (rotcnt), min, max);
+ r.intersect (r2);
+ if (!r.undefined_p ())
+ return false;
+ }
if (rotcnt == NULL_TREE)
return false;
swapped_p = i != 1;
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2023-01-17 11:19 [gcc r13-5223] forwprop: Fix up rotate pattern matching [PR106523] Jakub Jelinek
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