From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2153) id B30693858C60; Sun, 21 Apr 2024 04:08:36 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org B30693858C60 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1713672516; bh=70E/bfnMgzJV+Q3skU17swLimwHTKX+aOdLR9aC1yEw=; h=From:To:Subject:Date:From; b=dNRSzVM481L4Yth4JY+0XRyO7fCIkB9NjPQeAEQR9D0+4zuRkud0IrkVI17pxLxe9 II70vA2IYQKFtVtyWVDT0oldvdbb8O+oa0cTVwi/vq7uxL+aQdmdqxtaSyakSj5tim hnNnI74xSWIdWBTzq8/Uu+bJ3wEgrs7eI1NdxvfU= MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Jakub Jelinek To: gcc-cvs@gcc.gnu.org Subject: [gcc r13-8624] expr: Fix up emit_push_insn [PR114552] X-Act-Checkin: gcc X-Git-Author: Jakub Jelinek X-Git-Refname: refs/heads/releases/gcc-13 X-Git-Oldrev: cb277dea557aaa25fdced201f7c45c753c709dfa X-Git-Newrev: ba6fd407891fd83648ad803c85b607dc09e23be4 Message-Id: <20240421040836.B30693858C60@sourceware.org> Date: Sun, 21 Apr 2024 04:08:36 +0000 (GMT) List-Id: https://gcc.gnu.org/g:ba6fd407891fd83648ad803c85b607dc09e23be4 commit r13-8624-gba6fd407891fd83648ad803c85b607dc09e23be4 Author: Jakub Jelinek Date: Wed Apr 3 09:59:45 2024 +0200 expr: Fix up emit_push_insn [PR114552] r13-990 added optimizations in multiple spots to optimize during expansion storing of constant initializers into targets. In the load_register_parameters and expand_expr_real_1 cases, it checks it has a tree as the source and so knows we are reading that whole decl's value, so the code is fine as is, but in the emit_push_insn case it checks for a MEM from which something is pushed and checks for SYMBOL_REF as the MEM's address, but still assumes the whole object is copied, which as the following testcase shows might not always be the case. In the testcase, k is 6 bytes, then 2 bytes of padding, then another 4 bytes, while the emit_push_insn wants to store just the 6 bytes. The following patch simply verifies it is the whole initializer that is being stored, I think that is best thing to do so late in GCC 14 cycle as well for backporting. For GCC 15, perhaps the code could stop requiring it must be at offset zero, nor that the size is equal, but could use get_symbol_constant_value/fold_ctor_reference gimple-fold APIs to actually extract just part of the initializer if we e.g. push just some subset (of course, still verify that it is a subset). For sizes which are power of two bytes and we have some integer modes, we could use as type for fold_ctor_reference corresponding integral types, otherwise dunno, punt or use some structure (e.g. try to find one in the initializer?), whatever. But even in the other spots it could perhaps handle loading of COMPONENT_REFs or MEM_REFs from the .rodata vars. 2024-04-03 Jakub Jelinek PR middle-end/114552 * expr.cc (emit_push_insn): Only use store_constructor for immediate_const_ctor_p if int_expr_size matches size. * gcc.c-torture/execute/pr114552.c: New test. (cherry picked from commit 03039744f368a24a452e4ea8d946e9c2cedaf1aa) Diff: --- gcc/expr.cc | 9 ++++++--- gcc/testsuite/gcc.c-torture/execute/pr114552.c | 24 ++++++++++++++++++++++++ 2 files changed, 30 insertions(+), 3 deletions(-) diff --git a/gcc/expr.cc b/gcc/expr.cc index f8f5cc5a6ca..5dac06fa94b 100644 --- a/gcc/expr.cc +++ b/gcc/expr.cc @@ -5084,6 +5084,7 @@ emit_push_insn (rtx x, machine_mode mode, tree type, rtx size, /* If source is a constant VAR_DECL with a simple constructor, store the constructor to the stack instead of moving it. */ const_tree decl; + HOST_WIDE_INT sz; if (partial == 0 && MEM_P (xinner) && SYMBOL_REF_P (XEXP (xinner, 0)) @@ -5091,9 +5092,11 @@ emit_push_insn (rtx x, machine_mode mode, tree type, rtx size, && VAR_P (decl) && TREE_READONLY (decl) && !TREE_SIDE_EFFECTS (decl) - && immediate_const_ctor_p (DECL_INITIAL (decl), 2)) - store_constructor (DECL_INITIAL (decl), target, 0, - int_expr_size (DECL_INITIAL (decl)), false); + && immediate_const_ctor_p (DECL_INITIAL (decl), 2) + && (sz = int_expr_size (DECL_INITIAL (decl))) > 0 + && CONST_INT_P (size) + && INTVAL (size) == sz) + store_constructor (DECL_INITIAL (decl), target, 0, sz, false); else emit_block_move (target, xinner, size, BLOCK_OP_CALL_PARM); } diff --git a/gcc/testsuite/gcc.c-torture/execute/pr114552.c b/gcc/testsuite/gcc.c-torture/execute/pr114552.c new file mode 100644 index 00000000000..22cb4ee351f --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/execute/pr114552.c @@ -0,0 +1,24 @@ +/* PR middle-end/114552 */ + +struct __attribute__((packed)) S { short b; int c; }; +struct T { struct S b; int e; }; +static const struct T k = { { 1, 0 }, 0 }; + +__attribute__((noinline)) void +foo (void) +{ + asm volatile ("" : : : "memory"); +} + +__attribute__((noinline)) void +bar (struct S n) +{ + foo (); +} + +int +main () +{ + bar (k.b); + return 0; +}