[gcc r14-4695] ssa_name_has_boolean_range vs signed-boolean:31 types

[gcc r14-4695] ssa_name_has_boolean_range vs signed-boolean:31 types

[Andrew Pinski]

https://gcc.gnu.org/g:5e4abf4233cd34212680cca700d6438445e6a16a

commit r14-4695-g5e4abf4233cd34212680cca700d6438445e6a16a
Author: Andrew Pinski <apinski@marvell.com>
Date:   Fri Sep 1 22:09:08 2023 +0000

    ssa_name_has_boolean_range vs signed-boolean:31 types
    
    This turns out to be a latent bug in ssa_name_has_boolean_range
    where it would return true for all boolean types but all of the
    uses of ssa_name_has_boolean_range was expecting 0/1 as the range
    rather than [-1,0].
    So when I fixed vector lower to do all comparisons in boolean_type
    rather than still in the signed-boolean:31 type (to fix a different issue),
    the pattern in match for `-(type)!A -> (type)A - 1.` would assume A (which
    was signed-boolean:31) had a range of [0,1] which broke down and sometimes
    gave us -1/-2 as values rather than what we were expecting of -1/0.
    
    This was the simpliest patch I found while testing.
    
    We have another way of matching [0,1] range which we could use instead
    of ssa_name_has_boolean_range except that uses only the global ranges
    rather than the local range (during VRP).
    I tried to clean this up slightly by using gimple_match_zero_one_valuedp
    inside ssa_name_has_boolean_range but that failed because due to using
    only the global ranges. I then tried to change get_nonzero_bits to use
    the local ranges at the optimization time but that failed also because
    we would remove branches to __builtin_unreachable during evrp and lose
    information as we don't set the global ranges during evrp.
    
    OK? Bootstrapped and tested on x86_64-linux-gnu.
    
            PR tree-optimization/110817
    
    gcc/ChangeLog:
    
            * tree-ssanames.cc (ssa_name_has_boolean_range): Remove the
            check for boolean type as they don't have "[0,1]" range.
    
    gcc/testsuite/ChangeLog:
    
            * gcc.c-torture/execute/pr110817-1.c: New test.
            * gcc.c-torture/execute/pr110817-2.c: New test.
            * gcc.c-torture/execute/pr110817-3.c: New test.

Diff:
---
 gcc/testsuite/gcc.c-torture/execute/pr110817-1.c | 13 +++++++++++++
 gcc/testsuite/gcc.c-torture/execute/pr110817-2.c | 16 ++++++++++++++++
 gcc/testsuite/gcc.c-torture/execute/pr110817-3.c | 14 ++++++++++++++
 gcc/tree-ssanames.cc                             |  4 ----
 4 files changed, 43 insertions(+), 4 deletions(-)

diff --git a/gcc/testsuite/gcc.c-torture/execute/pr110817-1.c b/gcc/testsuite/gcc.c-torture/execute/pr110817-1.c
new file mode 100644
index 000000000000..1d33fa9a207b
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr110817-1.c
@@ -0,0 +1,13 @@
+typedef unsigned long __attribute__((__vector_size__ (8))) V;
+
+
+V c;
+
+int
+main (void)
+{
+  V v = ~((V) { } <=0);
+  if (v[0])
+    __builtin_abort ();
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.c-torture/execute/pr110817-2.c b/gcc/testsuite/gcc.c-torture/execute/pr110817-2.c
new file mode 100644
index 000000000000..1f759178425b
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr110817-2.c
@@ -0,0 +1,16 @@
+
+typedef unsigned char u8;
+typedef unsigned __attribute__((__vector_size__ (8))) V;
+
+V v;
+unsigned char c;
+
+int
+main (void)
+{
+  V x = (v > 0) > (v != c);
+ // V x = foo ();
+  if (x[0] || x[1])
+    __builtin_abort ();
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.c-torture/execute/pr110817-3.c b/gcc/testsuite/gcc.c-torture/execute/pr110817-3.c
new file mode 100644
index 000000000000..36f09c88dd99
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr110817-3.c
@@ -0,0 +1,14 @@
+typedef unsigned __attribute__((__vector_size__ (1*sizeof(unsigned)))) V;
+
+V v;
+unsigned char c;
+
+int
+main (void)
+{
+  V x = (v > 0) > (v != c);
+  volatile signed int t = x[0];
+  if (t)
+    __builtin_abort ();
+  return 0;
+}
diff --git a/gcc/tree-ssanames.cc b/gcc/tree-ssanames.cc
index 0a32444fbdf9..e26ef55b2bf5 100644
--- a/gcc/tree-ssanames.cc
+++ b/gcc/tree-ssanames.cc
@@ -522,10 +522,6 @@ ssa_name_has_boolean_range (tree op)
 {
   gcc_assert (TREE_CODE (op) == SSA_NAME);
 
-  /* Boolean types always have a range [0..1].  */
-  if (TREE_CODE (TREE_TYPE (op)) == BOOLEAN_TYPE)
-    return true;
-
   /* An integral type with a single bit of precision.  */
   if (INTEGRAL_TYPE_P (TREE_TYPE (op))
       && TYPE_UNSIGNED (TREE_TYPE (op))