From: Richard Biener <rguenther@suse.de>
To: gcc-patches@gcc.gnu.org
Subject: [PATCH] tree-optimization/108547 - robustify uninit predicate analysis
Date: Thu, 26 Jan 2023 13:49:04 +0100 (CET) [thread overview]
Message-ID: <20230126124904.81D8013A09@imap2.suse-dmz.suse.de> (raw)
Predicate analysis, when looking through casts doesn't bother to
convert boundary constants to the type of the bounded variables.
The following robustifies value_sat_pred_p to use widest_ints
to deal with this, like other code in predicate analysis.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.
PR tree-optimization/108547
* gimple-predicate-analysis.cc (value_sat_pred_p):
Use widest_int.
* gcc.dg/uninit-pr108547.c: New testcase.
---
gcc/gimple-predicate-analysis.cc | 6 +++---
gcc/testsuite/gcc.dg/uninit-pr108547.c | 24 ++++++++++++++++++++++++
2 files changed, 27 insertions(+), 3 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/uninit-pr108547.c
diff --git a/gcc/gimple-predicate-analysis.cc b/gcc/gimple-predicate-analysis.cc
index a7719ff493f..094e8c7aff3 100644
--- a/gcc/gimple-predicate-analysis.cc
+++ b/gcc/gimple-predicate-analysis.cc
@@ -728,11 +728,11 @@ value_sat_pred_p (tree val, tree boundary, tree_code cmpc,
if (cmpc != BIT_AND_EXPR)
return is_value_included_in (val, boundary, cmpc);
- wide_int andw = wi::to_wide (val) & wi::to_wide (boundary);
+ widest_int andw = wi::to_widest (val) & wi::to_widest (boundary);
if (exact_p)
- return andw == wi::to_wide (val);
+ return andw == wi::to_widest (val);
- return andw.to_uhwi ();
+ return wi::ne_p (andw, 0);
}
/* Return true if the domain of single predicate expression PRED1
diff --git a/gcc/testsuite/gcc.dg/uninit-pr108547.c b/gcc/testsuite/gcc.dg/uninit-pr108547.c
new file mode 100644
index 00000000000..d8f6c9ff87a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/uninit-pr108547.c
@@ -0,0 +1,24 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -Wuninitialized" } */
+
+int func_7_uc_10li_19 (int);
+int li_4, li_5, us_8;
+unsigned char func_7_ptr_13, func_7_uc_14;
+void func_7_ptr_18() {
+ if (li_5) {
+ for (;;)
+ ;
+ short s_15;
+ for (; func_7_uc_14;) {
+ us_8 = 7;
+ for (; us_8; us_8 += 1)
+ lblD2AF1FAB:
+ if (us_8)
+ li_4 = 1;
+ func_7_uc_14 += (__INTPTR_TYPE__)func_7_ptr_18;
+ if (func_7_ptr_13 & 1 && (func_7_uc_14 &= func_7_ptr_13))
+ s_15 %= func_7_uc_10li_19(s_15); /* { dg-warning "uninitialized" } */
+ }
+ }
+ goto lblD2AF1FAB;
+}
--
2.35.3
reply other threads:[~2023-01-26 12:49 UTC|newest]
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