On Thu, 3 Jul 2025, Icen Zeyada wrote:
> Generalize existing scalar gimple_fold rules to apply the same
> bitwise comparison simplifications to vector types. Previously, an
> expression like
>
> (x < y) && (x > y)
>
> would fold to `false` if x and y are scalars, but equivalent vector
> comparisons were left untouched. This patch enables folding of
> patterns of the form
>
> (cmp x y) bit_and (cmp x y)
> (cmp x y) bit_ior (cmp x y)
> (cmp x y) bit_xor (cmp x y)
>
> for vector operands as well, ensuring consistent optimization across
> all data types.
This patch looks good to me.
Thanks,
Richard.
> PR tree-optimization/119196
>
> gcc/ChangeLog:
>
> * match.pd: Allow scalar optimizations with bitwise AND/OR/XOR to apply
> to vectors.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/aarch64/vector-compare-5.c: Add new test for vector
> compare simplification.
>
> Signed-off-by: Icen Zeyada <icen.zeya...@arm.com>
> ---
> gcc/match.pd | 57 +++++++++++++---
> .../gcc.target/aarch64/vector-compare-5.c | 67 +++++++++++++++++++
> 2 files changed, 113 insertions(+), 11 deletions(-)
> create mode 100644 gcc/testsuite/gcc.target/aarch64/vector-compare-5.c
>
> diff --git a/gcc/match.pd b/gcc/match.pd
> index 36317b9128f..80c02a0ab02 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -3674,6 +3674,8 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> (if ((TREE_CODE (@1) == INTEGER_CST
> && TREE_CODE (@2) == INTEGER_CST)
> || ((INTEGRAL_TYPE_P (TREE_TYPE (@1))
> + || (VECTOR_TYPE_P (TREE_TYPE (@1))
> + && expand_vec_cmp_expr_p (TREE_TYPE (@1), type, code2))
> || POINTER_TYPE_P (TREE_TYPE (@1)))
> && bitwise_equal_p (@1, @2)))
> (with
> @@ -3712,27 +3714,39 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> (if (code1 == EQ_EXPR && val) @3)
> (if (code1 == EQ_EXPR && !val) { constant_boolean_node (false, type);
> })
> (if (code1 == NE_EXPR && !val && allbits) @4)
> - (if (code1 == NE_EXPR
> + (if ((code1 == NE_EXPR
> && code2 == GE_EXPR
> && cmp == 0
> && allbits)
> + && ((VECTOR_BOOLEAN_TYPE_P (type)
> + && expand_vec_cmp_expr_p (TREE_TYPE (@1), type, GT_EXPR))
> + || !VECTOR_TYPE_P (TREE_TYPE (@1))))
> (gt @c0 (convert @1)))
> - (if (code1 == NE_EXPR
> + (if ((code1 == NE_EXPR
> && code2 == LE_EXPR
> && cmp == 0
> && allbits)
> + && ((VECTOR_BOOLEAN_TYPE_P (type)
> + && expand_vec_cmp_expr_p (TREE_TYPE (@1), type, LT_EXPR))
> + || !VECTOR_TYPE_P (TREE_TYPE (@1))))
> (lt @c0 (convert @1)))
> /* (a != (b+1)) & (a > b) -> a > (b+1) */
> - (if (code1 == NE_EXPR
> + (if ((code1 == NE_EXPR
> && code2 == GT_EXPR
> && one_after
> && allbits)
> + && ((VECTOR_BOOLEAN_TYPE_P (type)
> + && expand_vec_cmp_expr_p (TREE_TYPE (@1), type, GT_EXPR))
> + || !VECTOR_TYPE_P (TREE_TYPE (@1))))
> (gt @c0 (convert @1)))
> /* (a != (b-1)) & (a < b) -> a < (b-1) */
> - (if (code1 == NE_EXPR
> + (if ((code1 == NE_EXPR
> && code2 == LT_EXPR
> && one_before
> && allbits)
> + && ((VECTOR_BOOLEAN_TYPE_P (type)
> + && expand_vec_cmp_expr_p (TREE_TYPE (@1), type, LT_EXPR))
> + || !VECTOR_TYPE_P (TREE_TYPE (@1))))
> (lt @c0 (convert @1)))
> )
> )
> @@ -3751,6 +3765,8 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> (if ((TREE_CODE (@1) == INTEGER_CST
> && TREE_CODE (@2) == INTEGER_CST)
> || ((INTEGRAL_TYPE_P (TREE_TYPE (@1))
> + || (VECTOR_TYPE_P (TREE_TYPE (@1))
> + && expand_vec_cmp_expr_p (TREE_TYPE (@1), type, code2))
> || POINTER_TYPE_P (TREE_TYPE (@1)))
> && operand_equal_p (@1, @2)))
> (with
> @@ -3801,6 +3817,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> (if ((TREE_CODE (@1) == INTEGER_CST
> && TREE_CODE (@2) == INTEGER_CST)
> || ((INTEGRAL_TYPE_P (TREE_TYPE (@1))
> + || (VECTOR_TYPE_P (TREE_TYPE (@1)))
> || POINTER_TYPE_P (TREE_TYPE (@1)))
> && bitwise_equal_p (@1, @2)))
> (with
> @@ -3842,24 +3859,36 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> (if (code1 == EQ_EXPR
> && code2 == GT_EXPR
> && cmp == 0
> - && allbits)
> + && allbits
> + && ((VECTOR_BOOLEAN_TYPE_P (type)
> + && expand_vec_cmp_expr_p (TREE_TYPE (@1), type, GE_EXPR))
> + || !VECTOR_TYPE_P (TREE_TYPE (@1))))
> (ge @c0 @2))
> (if (code1 == EQ_EXPR
> && code2 == LT_EXPR
> && cmp == 0
> - && allbits)
> + && allbits
> + && ((VECTOR_BOOLEAN_TYPE_P (type)
> + && expand_vec_cmp_expr_p (TREE_TYPE (@1), type, LE_EXPR))
> + || !VECTOR_TYPE_P (TREE_TYPE (@1))))
> (le @c0 @2))
> /* (a == (b-1)) | (a >= b) -> a >= (b-1) */
> (if (code1 == EQ_EXPR
> && code2 == GE_EXPR
> && one_before
> - && allbits)
> + && allbits
> + && ((VECTOR_BOOLEAN_TYPE_P (type)
> + && expand_vec_cmp_expr_p (TREE_TYPE (@1), type, GE_EXPR))
> + || !VECTOR_TYPE_P (TREE_TYPE (@1))))
> (ge @c0 (convert @1)))
> /* (a == (b+1)) | (a <= b) -> a <= (b-1) */
> (if (code1 == EQ_EXPR
> && code2 == LE_EXPR
> && one_after
> - && allbits)
> + && allbits
> + && ((VECTOR_BOOLEAN_TYPE_P (type)
> + && expand_vec_cmp_expr_p (TREE_TYPE (@1), type, LE_EXPR))
> + || !VECTOR_TYPE_P (TREE_TYPE (@1))))
> (le @c0 (convert @1)))
> )
> )
> @@ -3924,7 +3953,10 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> rcmp (ne le gt ne lt ge)
> (simplify
> (op:c (cmp1:c @0 @1) (cmp2 @0 @1))
> - (if (INTEGRAL_TYPE_P (TREE_TYPE (@0)) || POINTER_TYPE_P (TREE_TYPE (@0)))
> + (if (INTEGRAL_TYPE_P (TREE_TYPE (@0))
> + || POINTER_TYPE_P (TREE_TYPE (@0))
> + || (VECTOR_TYPE_P (TREE_TYPE (@1))
> + && expand_vec_cmp_expr_p (TREE_TYPE (@0), type, rcmp)))
> (rcmp @0 @1)))))
>
> /* Optimize (a CMP b) == (a CMP b) */
> @@ -3933,7 +3965,10 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> rcmp (eq gt le eq ge lt)
> (simplify
> (eq:c (cmp1:c @0 @1) (cmp2 @0 @1))
> - (if (INTEGRAL_TYPE_P (TREE_TYPE (@0)) || POINTER_TYPE_P (TREE_TYPE (@0)))
> + (if (INTEGRAL_TYPE_P (TREE_TYPE (@0))
> + || POINTER_TYPE_P (TREE_TYPE (@0))
> + || (VECTOR_TYPE_P (TREE_TYPE (@0))
> + && expand_vec_cmp_expr_p (TREE_TYPE (@0), type, rcmp)))
> (rcmp @0 @1))))
>
> /* (type)([0,1]@a != 0) -> (type)a
> @@ -11601,4 +11636,4 @@ and,
> && VECTOR_TYPE_P (type)
> && direct_internal_fn_supported_p (IFN_AVG_CEIL, type,
> OPTIMIZE_FOR_BOTH))
> (IFN_AVG_CEIL @0 @2)))
> -#endif
> +#endif
> \ No newline at end of file
> diff --git a/gcc/testsuite/gcc.target/aarch64/vector-compare-5.c
> b/gcc/testsuite/gcc.target/aarch64/vector-compare-5.c
> new file mode 100644
> index 00000000000..a1a601dc195
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/aarch64/vector-compare-5.c
> @@ -0,0 +1,67 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2" } */
> +/* { dg-additional-options "-fdump-tree-original-all" } */
> +
> +typedef int v4i __attribute__((vector_size(4*sizeof(int))));
> +
> +/* Ensure we can simplify `VEC_COND_EXPR(a OP1 b) OP2 VEC_COND_EXPR(a OP3 b)`
> + * into `VEC_COND_EXPR(a OP4 b)`
> + */
> +
> +void use (v4i const *z);
> +
> +void
> +g (v4i *x, v4i const *y, v4i *z, v4i *t)
> +{
> + *z = *x > *y | *x == *y; // expect >=
> + *t = *x > *y | *x <= *y; // expect true
> +}
> +
> +void
> +h (v4i *x, v4i const *y, v4i *z, v4i *t)
> +{
> + *z = *x <= *y & *x >= *y; // expect x == y
> + *t = *x <= *y & *x != *y; // expect x<y
> +}
> +
> +void
> +i (v4i *x, v4i const *y, v4i *z, v4i *t)
> +{
> + *z = *x == *y | *x != *y; // expect true
> + *t = *x == *y & *x != *y; // expect false
> +}
> +
> +void
> +k (v4i *x, v4i const *y, v4i *z, v4i *t)
> +{
> + *z = *x < *y | *x == *y; // x <= y
> + *t = *x < *y & *x > *y; // expect false
> +}
> +
> +void
> +m (v4i *x, v4i const *y, v4i *z, v4i *t)
> +{
> + *z = *x <= *y ^ *x >= *y; /* expect x != y */
> + *t = *x <= *y ^ *x != *y; /* expect x <= y */
> +}
> +
> +void
> +n (v4i *x, v4i const *y, v4i *z, v4i *t)
> +{
> + *z = *x == *y ^ *x != *y; /* expect true */
> + *t = *x == *y ^ *x == *y; /* expect false */
> +}
> +
> +
> +/* { dg-final { scan-tree-dump
> ".*\\*zD\\.\\d+\\s*=\\s*VEC_COND_EXPR\\s*<\\s*\\*xD\\.\\d+\\s*>=\\s*VIEW_CONVERT_EXPR<v4iD\\.\\d+>\\(\\*yD\\.\\d+\\)\\s*,\\s*\\{\\s*-1(,\\s*-1){3}\\s*\\}\\s*,\\s*\\{\\s*0(,\\s*0){3}\\s*\\}\\s*>\\s*;"
> "original" } } */
> +/* { dg-final { scan-tree-dump
> ".*\\*tD\\.\\d+\\s*=\\s*\\{\\s*-1(,\\s*-1){3}\\s*\\}\\s*;" "original" } } */
> +/* { dg-final { scan-tree-dump
> ".*\\*zD\\.\\d+\\s*=\\s*VEC_COND_EXPR\\s*<\\s*\\*xD\\.\\d+\\s*==\\s*VIEW_CONVERT_EXPR<v4iD\\.\\d+>\\(\\*yD\\.\\d+\\)\\s*,\\s*\\{\\s*-1(,\\s*-1){3}\\s*\\}\\s*,\\s*\\{\\s*0(,\\s*0){3}\\s*\\}\\s*>\\s*;"
> "original" } } */
> +/* { dg-final { scan-tree-dump
> ".*\\*tD\\.\\d+\\s*=\\s*VEC_COND_EXPR\\s*<\\s*\\*xD\\.\\d+\\s*<\\s*VIEW_CONVERT_EXPR<v4iD\\.\\d+>\\(\\*yD\\.\\d+\\)\\s*,\\s*\\{\\s*-1(,\\s*-1){3}\\s*\\}\\s*,\\s*\\{\\s*0(,\\s*0){3}\\s*\\}\\s*>\\s*;"
> "original" } } */
> +/* { dg-final { scan-tree-dump
> ".*\\*zD\\.\\d+\\s*=\\s*\\{\\s*-1(,\\s*-1){3}\\s*\\}\\s*;" "original" } } */
> +/* { dg-final { scan-tree-dump
> ".*\\*tD\\.\\d+\\s*=\\s*\\{\\s*0(,\\s*0){3}\\s*\\}\\s*;" "original" } } */
> +/* { dg-final { scan-tree-dump
> ".*\\*zD\\.\\d+\\s*=\\s*VEC_COND_EXPR\\s*<\\s*\\*xD\\.\\d+\\s*<=\\s*VIEW_CONVERT_EXPR<v4iD\\.\\d+>\\(\\*yD\\.\\d+\\)\\s*,\\s*\\{\\s*-1(,\\s*-1){3}\\s*\\}\\s*,\\s*\\{\\s*0(,\\s*0){3}\\s*\\}\\s*>\\s*;"
> "original" } } */
> +/* { dg-final { scan-tree-dump
> ".*\\*tD\\.\\d+\\s*=\\s*\\{\\s*0(,\\s*0){3}\\s*\\}\\s*;" "original" } } */
> +/* { dg-final { scan-tree-dump
> ".*\\*zD\\.\\d+\\s*=\\s*VEC_COND_EXPR\\s*<\\s*\\*xD\\.\\d+\\s*!=\\s*VIEW_CONVERT_EXPR<v4iD\\.\\d+>\\(\\*yD\\.\\d+\\)\\s*,\\s*\\{\\s*-1(,\\s*-1){3}\\s*\\}\\s*,\\s*\\{\\s*0(,\\s*0){3}\\s*\\}\\s*>\\s*;"
> "original" } } */
> +/* { dg-final { scan-tree-dump
> ".*\\*tD\\.\\d+\\s*=\\s*VEC_COND_EXPR\\s*<\\s*\\*xD\\.\\d+\\s*>=\\s*VIEW_CONVERT_EXPR<v4iD\\.\\d+>\\(\\*yD\\.\\d+\\)\\s*,\\s*\\{\\s*-1(,\\s*-1){3}\\s*\\}\\s*,\\s*\\{\\s*0(,\\s*0){3}\\s*\\}\\s*>\\s*;"
> "original" } } */
> +/* { dg-final { scan-tree-dump
> ".*\\*zD\\.\\d+\\s*=\\s*\\{\\s*-1(,\\s*-1){3}\\s*\\}\\s*;" "original" } } */
> +/* { dg-final { scan-tree-dump
> ".*\\*tD\\.\\d+\\s*=\\s*\\{\\s*0(,\\s*0){3}\\s*\\}\\s*;" "original" } } */
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH,
Frankenstrasse 146, 90461 Nuernberg, Germany;
GF: Ivo Totev, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)
