Hi!
As mentioned in the PR, the LSHIFT_EXPR computation of values that
will need longest or shortest string is both incorrect (it shifts
integer_one_node left, so for precisions above precision of integer
it returns 0 (not to mention that it is invalid GENERIC, because the types
of first operand and result have to match)) and unnecessary - every integral
type already has TYPE_MIN_VALUE and TYPE_MAX_VALUE readily available.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
Note, in the PR I've raised various further questions, Martin, can you look
at them?
2016-11-29 Jakub Jelinek <ja...@redhat.com>
PR tree-optimization/78586
* gimple-ssa-sprintf.c (format_integer): Use TYPE_MAX_VALUE or
TYPE_MIN_VALUE or build_all_ones_cst instead of folding LSHIFT_EXPR.
Don't build_int_cst min/max twice. Formatting fix.
* gcc.c-torture/execute/pr78586.c: New test.
--- gcc/gimple-ssa-sprintf.c.jj 2016-11-28 23:50:20.000000000 +0100
+++ gcc/gimple-ssa-sprintf.c 2016-11-29 15:54:17.605892667 +0100
@@ -1068,7 +1068,8 @@ format_integer (const conversion_spec &s
tree argmin = NULL_TREE;
tree argmax = NULL_TREE;
- if (arg && TREE_CODE (arg) == SSA_NAME
+ if (arg
+ && TREE_CODE (arg) == SSA_NAME
&& TREE_CODE (argtype) == INTEGER_TYPE)
{
/* Try to determine the range of values of the integer argument
@@ -1090,12 +1091,8 @@ format_integer (const conversion_spec &s
the upper bound for %i but -3 for %u. */
if (wi::neg_p (min) && !wi::neg_p (max))
{
- argmin = build_int_cst (argtype, wi::fits_uhwi_p (min)
- ? min.to_uhwi () : min.to_shwi ());
-
- argmax = build_int_cst (argtype, wi::fits_uhwi_p (max)
- ? max.to_uhwi () : max.to_shwi ());
-
+ argmin = res.argmin;
+ argmax = res.argmax;
int minbytes = format_integer (spec, res.argmin).range.min;
int maxbytes = format_integer (spec, res.argmax).range.max;
if (maxbytes < minbytes)
@@ -1154,21 +1151,25 @@ format_integer (const conversion_spec &s
int typeprec = TYPE_PRECISION (dirtype);
int argprec = TYPE_PRECISION (argtype);
- if (argprec < typeprec || POINTER_TYPE_P (argtype))
+ if (argprec < typeprec)
{
- if (TYPE_UNSIGNED (argtype))
+ if (POINTER_TYPE_P (argtype))
argmax = build_all_ones_cst (argtype);
+ else if (TYPE_UNSIGNED (argtype))
+ argmax = TYPE_MAX_VALUE (argtype);
else
- argmax = fold_build2 (LSHIFT_EXPR, argtype, integer_one_node,
- build_int_cst (integer_type_node,
- argprec - 1));
+ argmax = TYPE_MIN_VALUE (argtype);
}
else
{
- argmax = fold_build2 (LSHIFT_EXPR, dirtype, integer_one_node,
- build_int_cst (integer_type_node,
- typeprec - 1));
+ if (POINTER_TYPE_P (dirtype))
+ argmax = build_all_ones_cst (dirtype);
+ else if (TYPE_UNSIGNED (dirtype))
+ argmax = TYPE_MAX_VALUE (dirtype);
+ else
+ argmax = TYPE_MIN_VALUE (dirtype);
}
+
res.argmin = argmin;
res.argmax = argmax;
}
--- gcc/testsuite/gcc.c-torture/execute/pr78586.c.jj 2016-11-29
16:11:35.283742461 +0100
+++ gcc/testsuite/gcc.c-torture/execute/pr78586.c 2016-11-29
16:11:16.000000000 +0100
@@ -0,0 +1,17 @@
+/* PR tree-optimization/78586 */
+
+void
+foo (unsigned long x)
+{
+ char a[30];
+ unsigned long b = __builtin_sprintf (a, "%lu", x);
+ if (b != 4)
+ __builtin_abort ();
+}
+
+int
+main ()
+{
+ foo (1000);
+ return 0;
+}
Jakub
