tree-optimization/103361 - fix unroll-and-jam direction vector handling

Message ID 66n9q7pn-821q-r72p-ppo3-87s7r9968888@fhfr.qr
State New
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  • tree-optimization/103361 - fix unroll-and-jam direction vector handling
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Commit Message

Marek Polacek via Gcc-patches Nov. 23, 2021, 10:04 a.m.
This properly uses lambda_int instead of truncating the direction
vector to int which leads to false unexpected negative values.

Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.

2021-11-23  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/103361
	* gimple-loop-jam.c (adjust_unroll_factor): Use lambda_int
	for the dependence distance.
	* tree-data-ref.c (print_lambda_vector): Properly print a lambda_int.

	* g++.dg/torture/pr103361.C: New testcase.
---
 gcc/gimple-loop-jam.c                   |  4 ++--
 gcc/testsuite/g++.dg/torture/pr103361.C | 18 ++++++++++++++++++
 gcc/tree-data-ref.c                     |  2 +-
 3 files changed, 21 insertions(+), 3 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/torture/pr103361.C

-- 
2.31.1

Patch

diff --git a/gcc/gimple-loop-jam.c b/gcc/gimple-loop-jam.c
index 666f740f86d..933a4e0e6b0 100644
--- a/gcc/gimple-loop-jam.c
+++ b/gcc/gimple-loop-jam.c
@@ -402,10 +402,10 @@  adjust_unroll_factor (class loop *inner, struct data_dependence_relation *ddr,
 	     a >= N, or b > 0, or b is zero and a > 0.  Otherwise the unroll
 	     factor needs to be limited so that the first condition holds.
 	     That may limit the factor down to zero in the worst case.  */
-	  int dist = dist_v[0];
+	  lambda_int dist = dist_v[0];
 	  if (dist < 0)
 	    gcc_unreachable ();
-	  else if ((unsigned)dist >= *unroll)
+	  else if (dist >= (lambda_int)*unroll)
 	    ;
 	  else if (lambda_vector_zerop (dist_v + 1, DDR_NB_LOOPS (ddr) - 1))
 	    {
diff --git a/gcc/testsuite/g++.dg/torture/pr103361.C b/gcc/testsuite/g++.dg/torture/pr103361.C
new file mode 100644
index 00000000000..ec1d6e1bae4
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/pr103361.C
@@ -0,0 +1,18 @@ 
+/* { dg-do compile } */
+/* { dg-additional-options "-floop-unroll-and-jam" } */
+
+char a, b;
+extern unsigned short c[];
+extern bool d[];
+const unsigned short &e(const unsigned short &f, const unsigned short &g) {
+  if (g < f)
+    return g;
+  return f;
+}
+void k() {
+  for (int h = 0; b; h += 3)
+    for (unsigned long i = 0; i < 11104842004558084287ULL;
+         i += -11104842004558084300ULL)
+      for (bool j(e(6, e(6, c[h + i]))); j < (bool)a; j = 7)
+        d[7] = 0;
+}
diff --git a/gcc/tree-data-ref.c b/gcc/tree-data-ref.c
index 46f4ffedb48..9b6ca1a91e5 100644
--- a/gcc/tree-data-ref.c
+++ b/gcc/tree-data-ref.c
@@ -388,7 +388,7 @@  print_lambda_vector (FILE * outfile, lambda_vector vector, int n)
   int i;
 
   for (i = 0; i < n; i++)
-    fprintf (outfile, "%3d ", (int)vector[i]);
+    fprintf (outfile, HOST_WIDE_INT_PRINT_DEC " ", vector[i]);
   fprintf (outfile, "\n");
 }