From 2badc9885330b56dfabb49328c42de792bc67b1e Mon Sep 17 00:00:00 2001 From: Eric Botcazou Date: Tue, 5 May 2020 12:31:26 +0200 Subject: [PATCH] Do not put incomplete CONSTRUCTORs into static memory The CONSTRUCTOR_NO_CLEARING flag was invented to avoid generating a memset for CONSTRUCTORS that lack elements, but it turns out that the gimplifier can generate a memcpy for them instead, which is worse performance-wise, so this prevents it from doing that for them. * gimplify.c (gimplify_init_constructor): Do not put the constructor into static memory if it is not complete. --- gcc/ChangeLog | 5 +++++ gcc/gimplify.c | 2 +- gcc/testsuite/ChangeLog | 4 ++++ gcc/testsuite/gnat.dg/aggr29.adb | 12 ++++++++++++ 4 files changed, 22 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/gnat.dg/aggr29.adb diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 2267a63bca1..73634780e0f 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2020-05-05 Eric Botcazou + + * gimplify.c (gimplify_init_constructor): Do not put the constructor + into static memory if it is not complete. + 2020-05-05 Richard Biener PR tree-optimization/94949 diff --git a/gcc/gimplify.c b/gcc/gimplify.c index 2f2c51b2d89..7807e30fb2e 100644 --- a/gcc/gimplify.c +++ b/gcc/gimplify.c @@ -4995,8 +4995,8 @@ gimplify_init_constructor (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p, all-zero initializers (which aren't big enough to merit clearing), and don't try to make bitwise copies of TREE_ADDRESSABLE types. */ - if (valid_const_initializer + && complete_p && !(cleared || num_nonzero_elements == 0) && !TREE_ADDRESSABLE (type)) { diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 2ffa0f8f434..7f973949a7f 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2020-05-05 Eric Botcazou + + * gnat.dg/aggr29.adb: New test. + 2020-05-05 Richard Biener PR tree-optimization/94949 diff --git a/gcc/testsuite/gnat.dg/aggr29.adb b/gcc/testsuite/gnat.dg/aggr29.adb new file mode 100644 index 00000000000..c82a6f4c768 --- /dev/null +++ b/gcc/testsuite/gnat.dg/aggr29.adb @@ -0,0 +1,12 @@ +-- { dg-do compile } +-- { dg-options "-fdump-tree-gimple" } + +with Ada.Streams; use Ada.Streams; + +procedure Aggr29 is + A : aliased Stream_Element_Array := (1 .. 512 => <>); +begin + null; +end; + +-- { dg-final { scan-tree-dump-not "a___UNC = \\*" "gimple" } } -- 2.30.2