From: Jakub Jelinek Date: Tue, 14 Jul 2020 08:31:59 +0000 (+0200) Subject: openmp: Adjust outer bounds of non-rect loops X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6da60f76333666e98955aa33624a7e95bffe58aa;p=thirdparty%2Fgcc.git openmp: Adjust outer bounds of non-rect loops In loops like: #pragma omp parallel for collapse(2) for (i = -4; i < 8; i++) for (j = 3 * i; j > 2 * i; j--) for some outer loop iterations there are no inner loop iterations at all, the condition is false. In order to use Summæ Potestate to count number of iterations or to transform the logical iteration number to actual iterator values using quadratic non-equation root discovery the outer iterator range needs to be adjusted, such that the inner loop has at least one iteration for each of the outer loop iterator value in the reduced range. Sometimes this adjustment is done at the start of the range, at other times at the end. This patch implements it during the compile time number of loop computation (if all expressions are compile time constants). 2020-07-14 Jakub Jelinek * omp-general.h (struct omp_for_data): Add adjn1 member. * omp-general.c (omp_extract_for_data): For non-rect loop, punt on count computing if n1, n2 or step are not INTEGER_CST earlier. Narrow the outer iterator range if needed so that non-rect loop has at least one iteration for each outer range iteration. Compute adjn1. * omp-expand.c (expand_omp_for_init_vars): Use adjn1 if non-NULL instead of the outer loop's n1. * testsuite/libgomp.c/loop-21.c: New test. (cherry picked from commit f418bd4b92a03ee0ec0fe4cfcd896e86e11ac2cf) --- diff --git a/gcc/ChangeLog.omp b/gcc/ChangeLog.omp index 60951ac6be67..648d7376a1f5 100644 --- a/gcc/ChangeLog.omp +++ b/gcc/ChangeLog.omp @@ -1,3 +1,17 @@ +2021-02-09 Kwok Cheung Yeung + + Backport from mainline + 2020-07-14 Jakub Jelinek + + * omp-general.h (struct omp_for_data): Add adjn1 member. + * omp-general.c (omp_extract_for_data): For non-rect loop, punt on + count computing if n1, n2 or step are not INTEGER_CST earlier. + Narrow the outer iterator range if needed so that non-rect loop + has at least one iteration for each outer range iteration. Compute + adjn1. + * omp-expand.c (expand_omp_for_init_vars): Use adjn1 if non-NULL + instead of the outer loop's n1. + 2021-02-09 Kwok Cheung Yeung Backport from mainline diff --git a/gcc/omp-expand.c b/gcc/omp-expand.c index 449a0dcad0e2..87db86379dbb 100644 --- a/gcc/omp-expand.c +++ b/gcc/omp-expand.c @@ -2276,6 +2276,7 @@ expand_omp_for_init_vars (struct omp_for_data *fd, gimple_stmt_iterator *gsi, && (optab_handler (sqrt_optab, TYPE_MODE (double_type_node)) != CODE_FOR_nothing)) { + tree outer_n1 = fd->adjn1 ? fd->adjn1 : fd->loops[i - 1].n1; tree itype = TREE_TYPE (fd->loops[i].v); tree min_inner_iterations = fd->min_inner_iterations; tree factor = fd->factor; @@ -2398,7 +2399,7 @@ expand_omp_for_init_vars (struct omp_for_data *fd, gimple_stmt_iterator *gsi, *gsi = gsi_after_labels (e->dest); t = fold_convert (itype, c); t = fold_build2 (MULT_EXPR, itype, t, fd->loops[i - 1].step); - t = fold_build2 (PLUS_EXPR, itype, fd->loops[i - 1].n1, t); + t = fold_build2 (PLUS_EXPR, itype, outer_n1, t); t = force_gimple_operand_gsi (gsi, t, true, NULL_TREE, false, GSI_CONTINUE_LINKING); expand_omp_build_assign (gsi, fd->loops[i - 1].v, t, true); diff --git a/gcc/omp-general.c b/gcc/omp-general.c index be007aa83245..e0d7128f7532 100644 --- a/gcc/omp-general.c +++ b/gcc/omp-general.c @@ -214,6 +214,7 @@ omp_extract_for_data (gomp_for *for_stmt, struct omp_for_data *fd, fd->simd_schedule = false; fd->min_inner_iterations = NULL_TREE; fd->factor = NULL_TREE; + fd->adjn1 = NULL_TREE; collapse_iter = NULL; collapse_count = NULL; @@ -508,7 +509,10 @@ omp_extract_for_data (gomp_for *for_stmt, struct omp_for_data *fd, continue; if (single_nonrect == -1 || (loop->m1 && TREE_CODE (loop->m1) != INTEGER_CST) - || (loop->m2 && TREE_CODE (loop->m2) != INTEGER_CST)) + || (loop->m2 && TREE_CODE (loop->m2) != INTEGER_CST) + || TREE_CODE (loop->n1) != INTEGER_CST + || TREE_CODE (loop->n2) != INTEGER_CST + || TREE_CODE (loop->step) != INTEGER_CST) { count = NULL_TREE; continue; @@ -574,12 +578,129 @@ omp_extract_for_data (gomp_for *for_stmt, struct omp_for_data *fd, else if (t && t2 && integer_zerop (t) && integer_zerop (t2)) /* No iterations of the inner loop. count will be set to zero cst below. */; - else + else if (TYPE_UNSIGNED (itype) + || t == NULL_TREE + || t2 == NULL_TREE + || TREE_CODE (t) != INTEGER_CST + || TREE_CODE (t2) != INTEGER_CST) { /* Punt (for now). */ count = NULL_TREE; continue; } + else + { + /* Some iterations of the outer loop have zero iterations + of the inner loop, while others have at least one. + In this case, we need to adjust one of those outer + loop bounds. If ADJ_FIRST, we need to adjust outer n1 + (first), otherwise outer n2 (last). */ + bool adj_first = integer_zerop (t); + tree n1 = fold_convert (itype, loop->n1); + tree n2 = fold_convert (itype, loop->n2); + tree m1 = loop->m1 ? fold_convert (itype, loop->m1) + : build_zero_cst (itype); + tree m2 = loop->m2 ? fold_convert (itype, loop->m2) + : build_zero_cst (itype); + t = fold_binary (MINUS_EXPR, itype, n1, n2); + t2 = fold_binary (MINUS_EXPR, itype, m2, m1); + t = fold_binary (TRUNC_DIV_EXPR, itype, t, t2); + t2 = fold_binary (MINUS_EXPR, itype, t, first); + t2 = fold_binary (TRUNC_MOD_EXPR, itype, t2, ostep); + t = fold_binary (MINUS_EXPR, itype, t, t2); + tree n1cur + = fold_binary (PLUS_EXPR, itype, n1, + fold_binary (MULT_EXPR, itype, m1, t)); + tree n2cur + = fold_binary (PLUS_EXPR, itype, n2, + fold_binary (MULT_EXPR, itype, m2, t)); + t2 = fold_binary (loop->cond_code, boolean_type_node, + n1cur, n2cur); + tree t3 = fold_binary (MULT_EXPR, itype, m1, ostep); + tree t4 = fold_binary (MULT_EXPR, itype, m2, ostep); + tree diff; + if (adj_first) + { + tree new_first; + if (integer_nonzerop (t2)) + { + new_first = t; + n1first = n1cur; + n2first = n2cur; + if (flag_checking) + { + t3 = fold_binary (MINUS_EXPR, itype, n1cur, t3); + t4 = fold_binary (MINUS_EXPR, itype, n2cur, t4); + t3 = fold_binary (loop->cond_code, + boolean_type_node, t3, t4); + gcc_assert (integer_zerop (t3)); + } + } + else + { + t3 = fold_binary (PLUS_EXPR, itype, n1cur, t3); + t4 = fold_binary (PLUS_EXPR, itype, n2cur, t4); + new_first = fold_binary (PLUS_EXPR, itype, t, ostep); + n1first = t3; + n2first = t4; + if (flag_checking) + { + t3 = fold_binary (loop->cond_code, + boolean_type_node, t3, t4); + gcc_assert (integer_nonzerop (t3)); + } + } + diff = fold_binary (MINUS_EXPR, itype, new_first, first); + first = new_first; + fd->adjn1 = first; + } + else + { + tree new_last; + if (integer_zerop (t2)) + { + t3 = fold_binary (MINUS_EXPR, itype, n1cur, t3); + t4 = fold_binary (MINUS_EXPR, itype, n2cur, t4); + new_last = fold_binary (MINUS_EXPR, itype, t, ostep); + n1last = t3; + n2last = t4; + if (flag_checking) + { + t3 = fold_binary (loop->cond_code, + boolean_type_node, t3, t4); + gcc_assert (integer_nonzerop (t3)); + } + } + else + { + new_last = t; + n1last = n1cur; + n2last = n2cur; + if (flag_checking) + { + t3 = fold_binary (PLUS_EXPR, itype, n1cur, t3); + t4 = fold_binary (PLUS_EXPR, itype, n2cur, t4); + t3 = fold_binary (loop->cond_code, + boolean_type_node, t3, t4); + gcc_assert (integer_zerop (t3)); + } + } + diff = fold_binary (MINUS_EXPR, itype, last, new_last); + } + if (TYPE_UNSIGNED (itype) + && single_nonrect_cond_code == GT_EXPR) + diff = fold_binary (TRUNC_DIV_EXPR, itype, + fold_unary (NEGATE_EXPR, itype, diff), + fold_unary (NEGATE_EXPR, itype, + ostep)); + else + diff = fold_binary (TRUNC_DIV_EXPR, itype, diff, ostep); + diff = fold_convert (long_long_unsigned_type_node, diff); + single_nonrect_count + = fold_binary (MINUS_EXPR, long_long_unsigned_type_node, + single_nonrect_count, diff); + t = NULL_TREE; + } } else t = fold_binary (loop->cond_code, boolean_type_node, @@ -715,10 +836,11 @@ omp_extract_for_data (gomp_for *for_stmt, struct omp_for_data *fd, *collapse_count = fold_convert_loc (loc, iter_type, count); if (fd->min_inner_iterations && fd->factor) { - t = make_tree_vec (3); + t = make_tree_vec (4); TREE_VEC_ELT (t, 0) = *collapse_count; TREE_VEC_ELT (t, 1) = fd->min_inner_iterations; TREE_VEC_ELT (t, 2) = fd->factor; + TREE_VEC_ELT (t, 3) = fd->adjn1; *collapse_count = t; } } @@ -736,6 +858,7 @@ omp_extract_for_data (gomp_for *for_stmt, struct omp_for_data *fd, gcc_assert (fd->non_rect); fd->min_inner_iterations = TREE_VEC_ELT (fd->loop.n2, 1); fd->factor = TREE_VEC_ELT (fd->loop.n2, 2); + fd->adjn1 = TREE_VEC_ELT (fd->loop.n2, 3); fd->loop.n2 = TREE_VEC_ELT (fd->loop.n2, 0); } fd->loop.step = build_int_cst (TREE_TYPE (fd->loop.v), 1); diff --git a/gcc/omp-general.h b/gcc/omp-general.h index d4b0aa37ac38..392434c3979a 100644 --- a/gcc/omp-general.h +++ b/gcc/omp-general.h @@ -86,6 +86,8 @@ struct omp_for_data outer iterator, depending on which results in fewer iterations. */ tree factor; /* (m2 - m1) * outer_step / inner_step. */ + /* Adjusted n1 of the outer loop in such loop nests (if needed). */ + tree adjn1; }; #define OACC_FN_ATTRIB "oacc function" diff --git a/libgomp/ChangeLog.omp b/libgomp/ChangeLog.omp index dbfacc833080..364d02a45041 100644 --- a/libgomp/ChangeLog.omp +++ b/libgomp/ChangeLog.omp @@ -1,3 +1,10 @@ +2021-02-09 Kwok Cheung Yeung + + Backport from mainline + 2020-07-14 Jakub Jelinek + + * testsuite/libgomp.c/loop-21.c: New test. + 2021-02-09 Kwok Cheung Yeung Backport from mainline diff --git a/libgomp/testsuite/libgomp.c/loop-21.c b/libgomp/testsuite/libgomp.c/loop-21.c new file mode 100644 index 000000000000..1baf13d84db1 --- /dev/null +++ b/libgomp/testsuite/libgomp.c/loop-21.c @@ -0,0 +1,230 @@ +/* { dg-do run } */ + +extern void abort (void); + +int x, i, j; +volatile int a, b, c, d, e, f, g, h; +int k[13][27]; + +int +main () +{ + int niters; + for (i = -4; i < 8; i++) + for (j = 3 * i; j > 2 * i; j--) + k[i + 5][j + 5] = 1; + a = -4; b = 8; c = 1; d = 3; e = 0; f = 2; g = 0; h = -1; + niters = 0; i = -100; j = -100; x = -100; + #pragma omp parallel for collapse(2) lastprivate (i, j, x) reduction(+:niters) + for (i = -4; i < 8; i++) + for (j = 3 * i; j > 2 * i; j--) + { + if (i < -4 || i >= 8 || j > 3 * i || j <= i * 2 || k[i + 5][j + 5] != 1) + abort (); + k[i + 5][j + 5]++; + x = i * 1024 + (j & 1023); + niters++; + } + if (i != 8 || j != 14 || x != 7183 || niters != 28) + abort (); + niters = 0; i = -100; j = -100; x = -100; + #pragma omp parallel for collapse(2) lastprivate (i, j, x) reduction(+:niters) + for (i = a; i < b; i += c) + for (j = d * i + e; j > g + i * f; j += h) + { + if (i < -4 || i >= 8 || j > 3 * i || j <= i * 2 || k[i + 5][j + 5] != 2) + abort (); + k[i + 5][j + 5]++; + x = i * 1024 + (j & 1023); + niters++; + } + if (i != 8 || j != 14 || x != 7183 || niters != 28) + abort (); + for (int i = -4; i < 8; i++) + for (int j = 3 * i; j > 2 * i; j--) + if (k[i + 5][j + 5] == 3) + k[i + 5][j + 5] = 0; + else + abort (); + for (i = -2; i < 4; i++) + for (j = -2 * i + 3; j > -3; j -= 2) + k[i + 5][j + 5] = 1; + a = -2; b = 4; c = 1; d = -2; e = 3; f = 0; g = -3; h = -2; + niters = 0; i = -100; j = -100; x = -100; + #pragma omp parallel for collapse(2) lastprivate (i, j, x) reduction(+:niters) + for (i = -2; i < 4; i++) + for (j = -2 * i + 3; j > -3; j -= 2) + { + if (i < -2 || i >= 4 || j <= -3 || j > -2 * i + 3 || k[i + 5][j + 5] != 1) + abort (); + k[i + 5][j + 5]++; + x = i * 1024 + (j & 1023); + niters++; + } + if (/* i != 4 || j != -3 || */x != 3071 || niters != 15) + abort (); + niters = 0; i = -100; j = -100; x = -100; + #pragma omp parallel for collapse(2) lastprivate (i, j, x) reduction(+:niters) + for (i = a; i < b; i += c) + for (j = d * i + e; j > g + i * f; j += h) + { + if (i < -2 || i >= 4 || j <= -3 || j > -2 * i + 3 || k[i + 5][j + 5] != 2) + abort (); + k[i + 5][j + 5]++; + x = i * 1024 + (j & 1023); + niters++; + } + if (/*i != 4 || j != -3 || */x != 3071 || niters != 15) + abort (); + for (i = -2; i < 4; i++) + for (j = -2 * i + 3; j > -3; j -= 2) + if (k[i + 5][j + 5] == 3) + k[i + 5][j + 5] = 0; + else + abort (); + for (i = 3; i > -3; i--) + for (j = -2 * i + 7; j > 2 * i + 1; j--) + k[i + 5][j + 5] = 1; + a = 3; b = -3; c = -1; d = -2; e = 7; f = 2; g = 1; h = -1; + niters = 0; i = -100; j = -100; x = -100; + #pragma omp parallel for collapse(2) lastprivate (i, j, x) reduction(+:niters) + for (i = 3; i > -3; i--) + for (j = -2 * i + 7; j > 2 * i + 1; j--) + { + if (i <= -3 || i > 3 || j <= 2 * i + 1 || j > -2 * i + 7 || k[i + 5][j + 5] != 1) + abort (); + k[i + 5][j + 5]++; + x = i * 1024 + (j & 1023); + niters++; + } + if (i != -3 || j != -3 || x != -1026 || niters != 32) + abort (); + niters = 0; i = -100; j = -100; x = -100; + #pragma omp parallel for collapse(2) lastprivate (i, j, x) reduction(+:niters) + for (i = a; i > b; i += c) + for (j = d * i + e; j > g + i * f; j += h) + { + if (i <= -3 || i > 3 || j <= 2 * i + 1 || j > -2 * i + 7 || k[i + 5][j + 5] != 2) + abort (); + k[i + 5][j + 5]++; + x = i * 1024 + (j & 1023); + niters++; + } + if (i != -3 || j != -3 || x != -1026 || niters != 32) + abort (); + for (i = 3; i > -3; i--) + for (j = -2 * i + 7; j > 2 * i + 1; j--) + if (k[i + 5][j + 5] == 3) + k[i + 5][j + 5] = 0; + else + abort (); + for (i = 3; i > -3; i--) + for (j = 2 * i + 7; j > -2 * i + 1; j--) + k[i + 5][j + 5] = 1; + a = 3; b = -3; c = -1; d = 2; e = 7; f = -2; g = 1; h = -1; + niters = 0; i = -100; j = -100; x = -100; + #pragma omp parallel for collapse(2) lastprivate (i, j, x) reduction(+:niters) + for (i = 3; i > -3; i--) + for (j = 2 * i + 7; j > -2 * i + 1; j--) + { + if (i <= -3 || i > 3 || j <= -2 * i + 1 || j > 2 * i + 7 || k[i + 5][j + 5] != 1) + abort (); + k[i + 5][j + 5]++; + x = i * 1024 + (j & 1023); + niters++; + } + if (/*i != -3 || j != 3 || */x != -1020 || niters != 50) + abort (); + niters = 0; i = -100; j = -100; x = -100; + #pragma omp parallel for collapse(2) lastprivate (i, j, x) reduction(+:niters) + for (i = a; i > b; i += c) + for (j = d * i + e; j > g + i * f; j += h) + { + if (i <= -3 || i > 3 || j <= -2 * i + 1 || j > 2 * i + 7 || k[i + 5][j + 5] != 2) + abort (); + k[i + 5][j + 5]++; + x = i * 1024 + (j & 1023); + niters++; + } + if (/*i != -3 || j != 3 || */x != -1020 || niters != 50) + abort (); + for (i = 3; i > -3; i--) + for (j = 2 * i + 7; j > -2 * i + 1; j--) + if (k[i + 5][j + 5] == 3) + k[i + 5][j + 5] = 0; + else + abort (); + for (i = 6; i > -6; i--) + for (j = 2 * i + 7; j <= -2 * i + 1; j++) + k[i + 5][j + 5] = 1; + a = 6; b = -6; c = -1; d = 2; e = 7; f = -2; g = 2; h = 1; + niters = 0; i = -100; j = -100; x = -100; + #pragma omp parallel for collapse(2) lastprivate (i, j, x) reduction(+:niters) + for (i = 6; i > -6; i--) + for (j = 2 * i + 7; j <= -2 * i + 1; j++) + { + if (i <= -6 || i > 6 || j < 2 * i + 7 || j >= -2 * i + 2 || k[i + 5][j + 5] != 1) + abort (); + k[i + 5][j + 5]++; + x = i * 1024 + (j & 1023); + niters++; + } + if (i != -6 || j != 12 || x != -5109 || niters != 36) + abort (); + niters = 0; i = -100; j = -100; x = -100; + #pragma omp parallel for collapse(2) lastprivate (i, j, x) reduction(+:niters) + for (i = a; i > b; i += c) + for (j = d * i + e; j < g + i * f; j += h) + { + if (i <= -6 || i > 6 || j < 2 * i + 7 || j >= -2 * i + 2 || k[i + 5][j + 5] != 2) + abort (); + k[i + 5][j + 5]++; + x = i * 1024 + (j & 1023); + niters++; + } + if (i != -6 || j != 12 || x != -5109 || niters != 36) + abort (); + for (i = 6; i > -6; i--) + for (j = 2 * i + 7; j <= -2 * i + 1; j++) + if (k[i + 5][j + 5] == 3) + k[i + 5][j + 5] = 0; + else + abort (); + for (i = 6; i > -6; i -= 2) + for (j = -2 * i + 7; j <= 2 * i + 1; j++) + k[i + 5][j + 5] = 1; + a = 6; b = -6; c = -2; d = -2; e = 7; f = 2; g = 2; h = 1; + niters = 0; i = -100; j = -100; x = -100; + #pragma omp parallel for collapse(2) lastprivate (i, j, x) reduction(+:niters) + for (i = 6; i > -6; i -= 2) + for (j = -2 * i + 7; j <= 2 * i + 1; j++) + { + if (i <= -6 || i > 6 || j < -2 * i + 7 || j >= 2 * i + 2 || k[i + 5][j + 5] != 1) + abort (); + k[i + 5][j + 5]++; + x = i * 1024 + (j & 1023); + niters++; + } + if (/*i != -6 || j != 15 || */x != 2053 || niters != 33) + abort (); + niters = 0; i = -100; j = -100; x = -100; + #pragma omp parallel for collapse(2) lastprivate (i, j, x) reduction(+:niters) + for (i = a; i > b; i += c) + for (j = d * i + e; j < g + i * f; j += h) + { + if (i <= -6 || i > 6 || j < -2 * i + 7 || j >= 2 * i + 2 || k[i + 5][j + 5] != 2) + abort (); + k[i + 5][j + 5]++; + x = i * 1024 + (j & 1023); + niters++; + } + if (/*i != -6 || j != 15 || */x != 2053 || niters != 33) + abort (); + for (i = 6; i > -6; i -= 2) + for (j = -2 * i + 7; j <= 2 * i + 1; j++) + if (k[i + 5][j + 5] == 3) + k[i + 5][j + 5] = 0; + else + abort (); + return 0; +}