From 514577c66b39fc321bec1c957130fbcd66207822 Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Fri, 3 Jan 2025 17:55:04 +0100 Subject: [PATCH] forwprop: Use tree_fits_shwi_p in check_ctz_array MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When touching the function yesterday, I was surprised to see just TREE_CODE (something) != INTEGER_CST checks followed by tree_to_shwi. That would ICE if the INTEGER_CST doesn't fit. I have actually not been able to reproduce an ICE for the elt case as the caller gives up if the precision of the array type is larger than 32 bits (but I think it is still cleaner to use it), the idx case can actually ICE e.g. on static const unsigned long long magic = 0x03f08c5392f756cdULL; static const char table[] = { 0, [0x8000000000000000ULL] = 1, 12, 2, 13, 22, 17, 3, 14, 33, 23, 36, 18, 58, 28, 4, 62, 15, 34, 26, 24, 48, 50, 37, 19, 55, 59, 52, 29, 44, 39, 5, 63, 11, 21, 16, 32, 35, 57, 27, 61, 25, 47, 49, 54, 51, 43, 38, 10, 20, 31, 56, 60, 46, 53, 42, 9, 30, 45, 41, 8, 40, 7, 6, }; int ctz (unsigned long x) { unsigned long lsb = x & -x; return table[(lsb * magic) >> 58]; } ~/src/gcc/obj20/gcc/cc1 -quiet /tmp/1.c -O2 -mbmi /tmp/1.c:2:19: warning: size of ‘table’ 9223372036854775871 bytes exceeds maximum object size 9223372036854775807 [-Wlarger-than=] 2 | static const char table[] = { | ^~~~~ during GIMPLE pass: forwprop /tmp/1.c: In function ‘ctz’: /tmp/1.c:13:1: internal compiler error: in tree_to_shwi, at tree.cc:6518 13 | } | ^ 0x2efa51f internal_error(char const*, ...) ../../gcc/diagnostic-global-context.cc:517 0xf3c617 fancy_abort(char const*, int, char const*) ../../gcc/diagnostic.cc:1722 0x949a36 tree_to_shwi(tree_node const*) ../../gcc/tree.cc:6518 0x949a36 tree_to_shwi(tree_node const*) ../../gcc/tree.cc:6516 0x18472d5 check_ctz_array ../../gcc/tree-ssa-forwprop.cc:2286 but given the 9223372036854775871 bytes long array I'm not sure it is appropriate for the testsuite. 2025-01-03 Jakub Jelinek * tree-ssa-forwprop.cc (check_ctz_array): Use tree_fits_shwi_p instead of just TREE_CODE tests for INTEGER_CST. --- gcc/tree-ssa-forwprop.cc | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/gcc/tree-ssa-forwprop.cc b/gcc/tree-ssa-forwprop.cc index b35f845a42a..2e09027db56 100644 --- a/gcc/tree-ssa-forwprop.cc +++ b/gcc/tree-ssa-forwprop.cc @@ -2278,9 +2278,9 @@ check_ctz_array (tree ctor, unsigned HOST_WIDE_INT mulc, FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), i, idx, elt) { - if (TREE_CODE (idx) != INTEGER_CST) + if (!tree_fits_shwi_p (idx)) return false; - if (TREE_CODE (elt) != INTEGER_CST && TREE_CODE (elt) != RAW_DATA_CST) + if (!tree_fits_shwi_p (elt) && TREE_CODE (elt) != RAW_DATA_CST) return false; unsigned HOST_WIDE_INT index = tree_to_shwi (idx);