Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu.
Pushed to trunk as r13-4456-g0b737090a69624.
gcc/analyzer/ChangeLog:
PR analyzer/107948
* region-model-manager.cc
(region_model_manager::maybe_fold_binop): Fold (0 - VAL) to -VAL.
* region-model.cc (region_model::eval_condition): Handle e.g.
"-X <= 0" as equivalent to X >= 0".
gcc/testsuite/ChangeLog:
PR analyzer/107948
* gcc.dg/analyzer/feasibility-pr107948.c: New test.
Signed-off-by: David Malcolm <dmalc...@redhat.com>
---
gcc/analyzer/region-model-manager.cc | 3 ++
gcc/analyzer/region-model.cc | 13 +++++
.../gcc.dg/analyzer/feasibility-pr107948.c | 49 +++++++++++++++++++
3 files changed, 65 insertions(+)
create mode 100644 gcc/testsuite/gcc.dg/analyzer/feasibility-pr107948.c
diff --git a/gcc/analyzer/region-model-manager.cc
b/gcc/analyzer/region-model-manager.cc
index ae63c664ae5..471a9272e41 100644
--- a/gcc/analyzer/region-model-manager.cc
+++ b/gcc/analyzer/region-model-manager.cc
@@ -620,6 +620,9 @@ region_model_manager::maybe_fold_binop (tree type, enum
tree_code op,
/* (VAL - 0) -> VAL. */
if (cst1 && zerop (cst1))
return get_or_create_cast (type, arg0);
+ /* (0 - VAL) -> -VAL. */
+ if (cst0 && zerop (cst0))
+ return get_or_create_unaryop (type, NEGATE_EXPR, arg1);
break;
case MULT_EXPR:
/* (VAL * 0). */
diff --git a/gcc/analyzer/region-model.cc b/gcc/analyzer/region-model.cc
index 91b868f7b16..4f623fd6ca3 100644
--- a/gcc/analyzer/region-model.cc
+++ b/gcc/analyzer/region-model.cc
@@ -3339,6 +3339,19 @@ region_model::eval_condition (const svalue *lhs,
return lhs_ts;
}
}
+ else if (const unaryop_svalue *unaryop
+ = lhs->dyn_cast_unaryop_svalue ())
+ {
+ if (unaryop->get_op () == NEGATE_EXPR)
+ {
+ /* e.g. "-X <= 0" is equivalent to X >= 0". */
+ tristate lhs_ts = eval_condition (unaryop->get_arg (),
+ swap_tree_comparison (op),
+ rhs);
+ if (lhs_ts.is_known ())
+ return lhs_ts;
+ }
+ }
}
/* Handle rejection of equality for comparisons of the initial values of
diff --git a/gcc/testsuite/gcc.dg/analyzer/feasibility-pr107948.c
b/gcc/testsuite/gcc.dg/analyzer/feasibility-pr107948.c
new file mode 100644
index 00000000000..5eb8b0aef22
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/analyzer/feasibility-pr107948.c
@@ -0,0 +1,49 @@
+#include "analyzer-decls.h"
+
+void foo(int width) {
+ int i = 0;
+ int base;
+ if (width > 0){
+ __analyzer_eval(i == 0); /* { dg-warning "TRUE" } */
+ __analyzer_eval(width > 0); /* { dg-warning "TRUE" } */
+ __analyzer_eval(width - i > 0); /* { dg-warning "TRUE" } */
+ __analyzer_eval(i - width <= 0); /* { dg-warning "TRUE" } */
+ if (i - width <= 0) {
+ base = 512;
+ }
+ else {
+ __analyzer_dump_path (); /* { dg-bogus "path" } */
+ }
+ base+=1; /* { dg-bogus "uninit" } */
+ }
+}
+
+void test_ge_zero (int x)
+{
+ if (x >= 0)
+ {
+ __analyzer_eval(x >= 0); /* { dg-warning "TRUE" } */
+ __analyzer_eval(x > 0); /* { dg-warning "UNKNOWN" } */
+ __analyzer_eval(x <= 0); /* { dg-warning "UNKNOWN" } */
+ __analyzer_eval(x < 0); /* { dg-warning "FALSE" } */
+ __analyzer_eval(-x <= 0); /* { dg-warning "TRUE" } */
+ __analyzer_eval(-x < 0); /* { dg-warning "UNKNOWN" } */
+ __analyzer_eval(-x >= 0); /* { dg-warning "UNKNOWN" } */
+ __analyzer_eval(-x > 0); /* { dg-warning "FALSE" } */
+ }
+}
+
+void test_gt_zero (int x)
+{
+ if (x > 0)
+ {
+ __analyzer_eval(x >= 0); /* { dg-warning "TRUE" } */
+ __analyzer_eval(x > 0); /* { dg-warning "TRUE" } */
+ __analyzer_eval(x <= 0); /* { dg-warning "FALSE" } */
+ __analyzer_eval(x < 0); /* { dg-warning "FALSE" } */
+ __analyzer_eval(-x <= 0); /* { dg-warning "TRUE" } */
+ __analyzer_eval(-x < 0); /* { dg-warning "TRUE" } */
+ __analyzer_eval(-x >= 0); /* { dg-warning "FALSE" } */
+ __analyzer_eval(-x > 0); /* { dg-warning "FALSE" } */
+ }
+}
--
2.26.3
