Hi!
The following testcase is miscompiled since r12-3328.
That change assumed that if rhs1 of a GIMPLE_ASSIGN is COMPLEX_CST, then
that is the value of the lhs of the stmt, but that is not the case always,
only if it is a GIMPLE_SINGLE_RHS stmt. If it is e.g.
GIMPLE_UNARY_RHS or GIMPLE_BINARY_RHS (the latter happens in the testcase),
then it can be e.g.
__complex__ (3, 0) / var
and the REALPART_EXPR of that isn't 3, but the realpart of the division.
I assume once the ranger can do complex numbers adjust_*part_expr will just
fetch one or the other range from a underlying complex range, but until
then, we should limit this to what r12-3328 meant to do.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2022-02-21 Jakub Jelinek <ja...@redhat.com>
PR tree-optimization/104604
* gimple-range-fold.cc (adjust_imagpart_expr, adjust_realpart_expr):
Only check if gimple_assign_rhs1 is COMPLEX_CST if
gimple_assign_rhs_code is COMPLEX_CST.
* gcc.c-torture/execute/pr104604.c: New test.
--- gcc/gimple-range-fold.cc.jj 2022-02-16 09:19:15.741557607 +0100
+++ gcc/gimple-range-fold.cc 2022-02-21 13:50:56.524481955 +0100
@@ -397,7 +397,8 @@ adjust_imagpart_expr (irange &res, const
}
return;
}
- if (is_gimple_assign (def_stmt))
+ if (is_gimple_assign (def_stmt)
+ && gimple_assign_rhs_code (def_stmt) == COMPLEX_CST)
{
tree cst = gimple_assign_rhs1 (def_stmt);
if (TREE_CODE (cst) == COMPLEX_CST)
@@ -422,7 +423,8 @@ adjust_realpart_expr (irange &res, const
if (!SSA_NAME_DEF_STMT (name))
return;
- if (is_gimple_assign (def_stmt))
+ if (is_gimple_assign (def_stmt)
+ && gimple_assign_rhs_code (def_stmt) == COMPLEX_CST)
{
tree cst = gimple_assign_rhs1 (def_stmt);
if (TREE_CODE (cst) == COMPLEX_CST)
--- gcc/testsuite/gcc.c-torture/execute/pr104604.c.jj 2022-02-21
14:02:01.190303071 +0100
+++ gcc/testsuite/gcc.c-torture/execute/pr104604.c 2022-02-21
14:01:25.941789588 +0100
@@ -0,0 +1,34 @@
+/* PR tree-optimization/104604 */
+
+unsigned char g;
+
+__attribute__((noipa))
+unsigned char
+foo (_Complex unsigned c)
+{
+ unsigned char v = g;
+ _Complex unsigned t = 3;
+ t /= c;
+ return v + t;
+}
+
+__attribute__((noipa))
+unsigned char
+bar (_Complex unsigned c)
+{
+ unsigned char v = g;
+ _Complex unsigned t = 42;
+ t /= c;
+ return v + t;
+}
+
+int
+main ()
+{
+ unsigned char x = foo (7);
+ if (x)
+ __builtin_abort ();
+ if (bar (7) != 6)
+ __builtin_abort ();
+ return 0;
+}
Jakub
