From 928af3bfe2bd34a803c3a371436463fd46b31e5d Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Wed, 23 Mar 2016 19:55:38 +0100 Subject: [PATCH] re PR c++/70001 (Infinity compilation time) PR c++/70001 * constexpr.c (cxx_eval_vec_init_1): Reuse CONSTRUCTOR initializers for 1..max even for multi-dimensional arrays. Call unshare_expr on it. * g++.dg/cpp0x/constexpr-70001-4.C: New test. * g++.dg/cpp1y/pr70001.C: New test. From-SVN: r234439 --- gcc/cp/ChangeLog | 5 ++ gcc/cp/constexpr.c | 39 +++++++++------ gcc/testsuite/ChangeLog | 4 ++ .../g++.dg/cpp0x/constexpr-70001-4.C | 13 +++++ gcc/testsuite/g++.dg/cpp1y/pr70001.C | 49 +++++++++++++++++++ 5 files changed, 96 insertions(+), 14 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp0x/constexpr-70001-4.C create mode 100644 gcc/testsuite/g++.dg/cpp1y/pr70001.C diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index b7a1f3984b1..42c70546378 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,5 +1,10 @@ 2016-03-23 Jakub Jelinek + PR c++/70001 + * constexpr.c (cxx_eval_vec_init_1): Reuse CONSTRUCTOR initializers + for 1..max even for multi-dimensional arrays. Call unshare_expr + on it. + PR c++/70323 * constexpr.c (cxx_eval_constant_expression): Diagnose overflow on TREE_OVERFLOW constants. diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c index 4baf11445df..8427513854d 100644 --- a/gcc/cp/constexpr.c +++ b/gcc/cp/constexpr.c @@ -2362,7 +2362,6 @@ cxx_eval_vec_init_1 (const constexpr_ctx *ctx, tree atype, tree init, vec **p = &CONSTRUCTOR_ELTS (ctx->ctor); vec_alloc (*p, max + 1); bool pre_init = false; - tree pre_init_elt = NULL_TREE; unsigned HOST_WIDE_INT i; /* For the default constructor, build up a call to the default @@ -2392,6 +2391,7 @@ cxx_eval_vec_init_1 (const constexpr_ctx *ctx, tree atype, tree init, { tree idx = build_int_cst (size_type_node, i); tree eltinit; + bool reuse = false; constexpr_ctx new_ctx; init_subob_ctx (ctx, new_ctx, idx, pre_init ? init : elttype); if (new_ctx.ctor != ctx->ctor) @@ -2400,7 +2400,10 @@ cxx_eval_vec_init_1 (const constexpr_ctx *ctx, tree atype, tree init, { /* A multidimensional array; recurse. */ if (value_init || init == NULL_TREE) - eltinit = NULL_TREE; + { + eltinit = NULL_TREE; + reuse = i == 0; + } else eltinit = cp_build_array_ref (input_location, init, idx, tf_warning_or_error); @@ -2412,18 +2415,9 @@ cxx_eval_vec_init_1 (const constexpr_ctx *ctx, tree atype, tree init, { /* Initializing an element using value or default initialization we just pre-built above. */ - if (pre_init_elt == NULL_TREE) - pre_init_elt - = cxx_eval_constant_expression (&new_ctx, init, lval, - non_constant_p, overflow_p); - eltinit = pre_init_elt; - /* Don't reuse the result of cxx_eval_constant_expression - call if it isn't a constant initializer or if it requires - relocations. */ - if (initializer_constant_valid_p (pre_init_elt, - TREE_TYPE (pre_init_elt)) - != null_pointer_node) - pre_init_elt = NULL_TREE; + eltinit = cxx_eval_constant_expression (&new_ctx, init, lval, + non_constant_p, overflow_p); + reuse = i == 0; } else { @@ -2449,6 +2443,23 @@ cxx_eval_vec_init_1 (const constexpr_ctx *ctx, tree atype, tree init, } else CONSTRUCTOR_APPEND_ELT (*p, idx, eltinit); + /* Reuse the result of cxx_eval_constant_expression call + from the first iteration to all others if it is a constant + initializer that doesn't require relocations. */ + if (reuse + && max > 1 + && (initializer_constant_valid_p (eltinit, TREE_TYPE (eltinit)) + == null_pointer_node)) + { + if (new_ctx.ctor != ctx->ctor) + eltinit = new_ctx.ctor; + for (i = 1; i < max; ++i) + { + idx = build_int_cst (size_type_node, i); + CONSTRUCTOR_APPEND_ELT (*p, idx, unshare_expr (eltinit)); + } + break; + } } if (!*non_constant_p) diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 8fbd1e86511..1b3283286c3 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,5 +1,9 @@ 2016-03-23 Jakub Jelinek + PR c++/70001 + * g++.dg/cpp0x/constexpr-70001-4.C: New test. + * g++.dg/cpp1y/pr70001.C: New test. + PR c++/70323 * g++.dg/cpp0x/constexpr-70323.C: New test. diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-70001-4.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-70001-4.C new file mode 100644 index 00000000000..c1ab1765b3e --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-70001-4.C @@ -0,0 +1,13 @@ +// PR c++/70001 +// { dg-do compile { target c++11 } } + +struct B +{ + int a; + constexpr B () : a (0) { } +}; + +struct A +{ + B b[1 << 19][1][1][1]; +} c; diff --git a/gcc/testsuite/g++.dg/cpp1y/pr70001.C b/gcc/testsuite/g++.dg/cpp1y/pr70001.C new file mode 100644 index 00000000000..adbb13251e6 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp1y/pr70001.C @@ -0,0 +1,49 @@ +// PR c++/70001 +// { dg-do compile { target c++14 } } + +struct B +{ + int a; + constexpr B () : a (0) { } + constexpr B (int x) : a (x) { } +}; +struct C +{ + B c; + constexpr C () : c (0) { } +}; +struct A +{ + B b[1 << 4]; +}; +struct D +{ + C d[1 << 4]; +}; + +constexpr int +foo (int a, int b) +{ + A c; + c.b[a].a += b; + c.b[b].a += a; + return c.b[0].a + c.b[a].a + c.b[b].a; +} + +constexpr int +bar (int a, int b) +{ + D c; + c.d[a].c.a += b; + c.d[b].c.a += a; + return c.d[0].c.a + c.d[a].c.a + c.d[b].c.a; +} + +constexpr int d = foo (1, 2); +constexpr int e = foo (0, 3); +constexpr int f = foo (2, 4); +constexpr int g = bar (1, 2); +constexpr int h = bar (0, 3); +constexpr int i = bar (2, 4); +static_assert (d == 3 && e == 6 && f == 6, ""); +static_assert (g == 3 && h == 6 && i == 6, ""); -- 2.30.2