match.pd had a rule to simplify ((X /[ex] A) +- B) * A -> X +- A * B
when A and B are INTEGER_CSTs. This patch extends it to handle the
case where the outer multiplication is by a factor of A, not just
A itself. It also handles addition and multiplication of poly_ints.
(Exact division by a poly_int seems unlikely.)
I'm not sure why minus is handled here. Wouldn't minus of a constant be
canonicalised to a plus?
gcc/
* match.pd: Generalise ((X /[ex] A) +- B) * A -> X +- A * B rule
to ((X /[ex] C1) +- C2) * (C1 * C3) -> (X * C3) +- (C1 * C2 * C3).
gcc/testsuite/
* gcc.dg/tree-ssa/mulexactdiv-5.c: New test.
* gcc.dg/tree-ssa/mulexactdiv-6.c: Likewise.
* gcc.dg/tree-ssa/mulexactdiv-7.c: Likewise.
* gcc.dg/tree-ssa/mulexactdiv-8.c: Likewise.
* gcc.target/aarch64/sve/cnt_fold_3.c: Likewise.
---
gcc/match.pd | 38 +++++++-----
gcc/testsuite/gcc.dg/tree-ssa/mulexactdiv-5.c | 29 +++++++++
gcc/testsuite/gcc.dg/tree-ssa/mulexactdiv-6.c | 59 +++++++++++++++++++
gcc/testsuite/gcc.dg/tree-ssa/mulexactdiv-7.c | 22 +++++++
gcc/testsuite/gcc.dg/tree-ssa/mulexactdiv-8.c | 20 +++++++
.../gcc.target/aarch64/sve/cnt_fold_3.c | 40 +++++++++++++
6 files changed, 194 insertions(+), 14 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/mulexactdiv-5.c
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/mulexactdiv-6.c
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/mulexactdiv-7.c
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/mulexactdiv-8.c
create mode 100644 gcc/testsuite/gcc.target/aarch64/sve/cnt_fold_3.c
diff --git a/gcc/match.pd b/gcc/match.pd
index 6677bc06d80..268316456c3 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -5493,24 +5493,34 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
optab_vector)))
(eq (trunc_mod @0 @1) { build_zero_cst (TREE_TYPE (@0)); })))
-/* ((X /[ex] A) +- B) * A --> X +- A * B. */
+/* ((X /[ex] C1) +- C2) * (C1 * C3) --> (X * C3) +- (C1 * C2 * C3). */
(for op (plus minus)
(simplify
- (mult (convert1? (op (convert2? (exact_div @0 INTEGER_CST@@1))
INTEGER_CST@2)) @1)
- (if (tree_nop_conversion_p (type, TREE_TYPE (@2))
- && tree_nop_conversion_p (TREE_TYPE (@0), TREE_TYPE (@2)))
- (with
- {
- wi::overflow_type overflow;
- wide_int mul = wi::mul (wi::to_wide (@1), wi::to_wide (@2),
- TYPE_SIGN (type), &overflow);
- }
+ (mult (convert1? (op (convert2? (exact_div @0 INTEGER_CST@1))
+ poly_int_tree_p@2))
+ poly_int_tree_p@3)
+ (with { poly_widest_int factor; }
+ (if (tree_nop_conversion_p (type, TREE_TYPE (@2))
+ && tree_nop_conversion_p (TREE_TYPE (@0), TREE_TYPE (@2))
+ && multiple_p (wi::to_poly_widest (@3), wi::to_widest (@1), &factor))
+ (with
+ {
+ wi::overflow_type overflow;
+ wide_int mul;
+ }
(if (types_match (type, TREE_TYPE (@2))
- && types_match (TREE_TYPE (@0), TREE_TYPE (@2)) && !overflow)
- (op @0 { wide_int_to_tree (type, mul); })
+ && types_match (TREE_TYPE (@0), TREE_TYPE (@2))
+ && TREE_CODE (@2) == INTEGER_CST
+ && TREE_CODE (@3) == INTEGER_CST
+ && (mul = wi::mul (wi::to_wide (@2), wi::to_wide (@3),
+ TYPE_SIGN (type), &overflow),
+ !overflow))
+ (op (mult @0 { wide_int_to_tree (type, factor); })
+ { wide_int_to_tree (type, mul); })
(with { tree utype = unsigned_type_for (type); }
- (convert (op (convert:utype @0)
- (mult (convert:utype @1) (convert:utype @2))))))))))
+ (convert (op (mult (convert:utype @0)
+ { wide_int_to_tree (utype, factor); })
+ (mult (convert:utype @3) (convert:utype @2)))))))))))
/* Canonicalization of binary operations. */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/mulexactdiv-5.c
b/gcc/testsuite/gcc.dg/tree-ssa/mulexactdiv-5.c
new file mode 100644
index 00000000000..37cd676fff6
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/mulexactdiv-5.c
@@ -0,0 +1,29 @@
+/* { dg-options "-O2 -fdump-tree-optimized-raw" } */
+
+#define TEST_CMP(FN, DIV, ADD, MUL) \
+ int \
+ FN (int x) \
+ { \
+ if (x & 7) \
+ __builtin_unreachable (); \
+ x /= DIV; \
+ x += ADD; \
+ return x * MUL; \
+ }
+
+TEST_CMP (f1, 2, 1, 6)
+TEST_CMP (f2, 2, 2, 10)
+TEST_CMP (f3, 4, 3, 80)
+TEST_CMP (f4, 8, 4, 200)
+
+/* { dg-final { scan-tree-dump-not {<[a-z]*_div_expr,} "optimized" } } */
+/* { dg-final { scan-tree-dump-not {<rshift_expr,} "optimized" } } */
+/* { dg-final { scan-tree-dump-not {<nop_expr,} "optimized" } } */
+/* { dg-final { scan-tree-dump {<mult_expr, [^,]*, [^,]*, 3,} "optimized" } }
*/
+/* { dg-final { scan-tree-dump {<mult_expr, [^,]*, [^,]*, 5,} "optimized" } }
*/
+/* { dg-final { scan-tree-dump {<mult_expr, [^,]*, [^,]*, 20,} "optimized" } }
*/
+/* { dg-final { scan-tree-dump {<mult_expr, [^,]*, [^,]*, 25,} "optimized" } }
*/
+/* { dg-final { scan-tree-dump {<plus_expr, [^,]*, [^,]*, 6,} "optimized" } }
*/
+/* { dg-final { scan-tree-dump {<plus_expr, [^,]*, [^,]*, 20,} "optimized" } }
*/
+/* { dg-final { scan-tree-dump {<plus_expr, [^,]*, [^,]*, 240,} "optimized" }
} */
+/* { dg-final { scan-tree-dump {<plus_expr, [^,]*, [^,]*, 800,} "optimized" }
} */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/mulexactdiv-6.c
b/gcc/testsuite/gcc.dg/tree-ssa/mulexactdiv-6.c
new file mode 100644
index 00000000000..927cb95b82b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/mulexactdiv-6.c
@@ -0,0 +1,59 @@
+/* { dg-options "-O2 -fwrapv -fdump-tree-optimized-raw" } */
+
+#define TEST_CMP(FN, DIV, ADD, MUL) \
+ int \
+ FN (int x) \
+ { \
+ if (x & 7) \
+ __builtin_unreachable (); \
+ x /= DIV; \
+ x += (int) (ADD); \
+ return x * MUL; \
+ }
+
+TEST_CMP (f1, 2, ~0U >> 1, 6)
+TEST_CMP (f2, 2, ~(~0U >> 2), 10)
+
+void
+cmp1 (int x)
+{
+ if (x & 3)
+ __builtin_unreachable ();
+
+ int y = x / 4;
+ y += (int) (~0U / 3U);
+ y *= 8;
+
+ unsigned z = x;
+ z *= 2U;
+ z += ~0U / 3U * 8U;
+
+ if (y != (int) z)
+ __builtin_abort ();
+}
+
+
+void
+cmp2 (int x)
+{
+ if (x & 63)
+ __builtin_unreachable ();
+
+ unsigned y = x / 64;
+ y += 100U;
+ int y2 = (int) y * 256;
+
+ unsigned z = x;
+ z *= 4U;
+ z += 25600U;
+
+ if (y2 != (int) z)
+ __builtin_abort ();
+}
+
+/* { dg-final { scan-tree-dump-not {<[a-z]*_div_expr,} "optimized" } } */
+/* { dg-final { scan-tree-dump-not {<rshift_expr,} "optimized" } } */
+/* { dg-final { scan-tree-dump-not {gimple_call <} "optimized" } } */
+/* { dg-final { scan-tree-dump-times {<nop_expr,} 4 "optimized" } } */
+/* { dg-final { scan-tree-dump-times {<mult_expr,} 2 "optimized" } } */
+/* { dg-final { scan-tree-dump-times {<plus_expr,} 2 "optimized" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/mulexactdiv-7.c
b/gcc/testsuite/gcc.dg/tree-ssa/mulexactdiv-7.c
new file mode 100644
index 00000000000..c6abce371db
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/mulexactdiv-7.c
@@ -0,0 +1,22 @@
+/* { dg-options "-O2 -fdump-tree-optimized-raw" } */
+
+typedef __PTRDIFF_TYPE__ ptrdiff_t;
+typedef __SIZE_TYPE__ size_t;
+
+void
+cmp1 (int *ptr1, int *ptr2)
+{
+ unsigned char x1 = ptr2 - ptr1;
+ x1 += 0x40;
+ ptrdiff_t x2 = (ptrdiff_t) x1 * (ptrdiff_t) 4;
+
+ ptrdiff_t y = ((char *) ptr2 - (char *) ptr1) + (ptrdiff_t) 0x100;
+
+ size_t z = (char *) ptr2 - (char *) ptr1;
+ z += (size_t) 0x100;
+
+ if (x2 != y && x2 != (ptrdiff_t) z)
+ __builtin_abort ();
+}
+
+/* { dg-final { scan-tree-dump {gimple_call <} "optimized" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/mulexactdiv-8.c
b/gcc/testsuite/gcc.dg/tree-ssa/mulexactdiv-8.c
new file mode 100644
index 00000000000..f452245d95d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/mulexactdiv-8.c
@@ -0,0 +1,20 @@
+/* { dg-options "-O2 -fdump-tree-optimized-raw" } */
+
+#define TEST_CMP(FN, DIV, ADD, MUL) \
+ int \
+ FN (int x) \
+ { \
+ if (x & 7) \
+ __builtin_unreachable (); \
+ x /= DIV; \
+ x += ADD; \
+ return x * MUL; \
+ }
+
+TEST_CMP (f1, 2, 1, 3)
+TEST_CMP (f2, 4, 2, 2)
+TEST_CMP (f3, 4, 3, 6)
+TEST_CMP (f4, 8, 4, 2)
+TEST_CMP (f5, 8, 5, 4)
+
+/* { dg-final { scan-tree-dump-times {<[a-z]*_div_expr,} 5 "optimized" } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/sve/cnt_fold_3.c
b/gcc/testsuite/gcc.target/aarch64/sve/cnt_fold_3.c
new file mode 100644
index 00000000000..f9c50e26e48
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/sve/cnt_fold_3.c
@@ -0,0 +1,40 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+/* { dg-final { check-function-bodies "**" "" } } */
+
+#include <arm_sve.h>
+
+/*
+** f1:
+** sub x0, x1, x0
+** incb x0
+** ret
+*/
+uint64_t
+f1 (int *ptr1, int *ptr2)
+{
+ return ((ptr2 - ptr1) + svcntw ()) * 4;
+}
+
+/*
+** f2:
+** sub x0, x1, x0
+** incb x0, all, mul #4
+** ret
+*/
+uint64_t
+f2 (int *ptr1, int *ptr2)
+{
+ return ((ptr2 - ptr1) + svcntb ()) * 4;
+}
+
+/*
+** f3:
+** sub x0, x1, x0
+** ret
+*/
+uint64_t
+f3 (int *ptr1, int *ptr2)
+{
+ return (((int *) ((char *) ptr2 + svcntb ()) - ptr1) - svcntw ()) * 4;
+}
--
2.25.1
