re PR tree-optimization/86990 (wrong code at -O2 on x86_64-linux-gnu in 64-bit mode)

	PR tree-optimization/86990
	* gimple-ssa-store-merging.c (imm_store_chain_info:coalesce_immediate):
	Check that the entire merged store group is made of constants only for
	overlapping stores.

From-SVN: r264458

4 files changed, 185 insertions, 4 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 8be6771..d71a70b 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2018-09-21  Eric Botcazou  <ebotcazou@adacore.com>
+
+	PR tree-optimization/86990
+	* gimple-ssa-store-merging.c (imm_store_chain_info:coalesce_immediate):
+	Check that the entire merged store group is made of constants only for
+	overlapping stores.
+
 2018-09-20  Allan Sandfeld Jensen  <allan.jensen@qt.io>
 
 	* gcc.c (LINK_COMMAND_SPEC): Handle -r like -nostdlib.
diff --git a/gcc/gimple-ssa-store-merging.c b/gcc/gimple-ssa-store-merging.c
index c8031e1..85dd5bc 100644
--- a/gcc/gimple-ssa-store-merging.c
+++ b/gcc/gimple-ssa-store-merging.c
@@ -2701,16 +2701,25 @@ imm_store_chain_info::coalesce_immediate_stores ()
 		    merged_store->start + merged_store->width - 1))
 	{
 	  /* Only allow overlapping stores of constants.  */
-	  if (info->rhs_code == INTEGER_CST
-	      && merged_store->stores[0]->rhs_code == INTEGER_CST)
+	  if (info->rhs_code == INTEGER_CST)
 	    {
+	      bool only_constants = true;
+	      store_immediate_info *infoj;
+	      unsigned int j;
+	      FOR_EACH_VEC_ELT (merged_store->stores, j, infoj)
+		if (infoj->rhs_code != INTEGER_CST)
+		  {
+		    only_constants = false;
+		    break;
+		  }
 	      unsigned int last_order
 		= MAX (merged_store->last_order, info->order);
 	      unsigned HOST_WIDE_INT end
 		= MAX (merged_store->start + merged_store->width,
 		       info->bitpos + info->bitsize);
-	      if (check_no_overlap (m_store_info, i, INTEGER_CST,
-				    last_order, end))
+	      if (only_constants
+		  && check_no_overlap (m_store_info, i, INTEGER_CST,
+				       last_order, end))
 		{
 		  /* check_no_overlap call above made sure there are no
 		     overlapping stores with non-INTEGER_CST rhs_code
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 3b73194..c68e2c6 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2018-09-21  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gcc.c-torture/execute/20180921-1.c: New test.
+
 2018-09-20  Marek Polacek  <polacek@redhat.com>
 
 	PR c++/87109 - wrong ctor with maybe-rvalue semantics.
diff --git a/gcc/testsuite/gcc.c-torture/execute/20180921-1.c b/gcc/testsuite/gcc.c-torture/execute/20180921-1.c
new file mode 100644
index 0000000..50d4faa
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/20180921-1.c
@@ -0,0 +1,161 @@
+/* PR tree-optimization/86990 */
+/* Testcase by Zhendong Su <su@cs.ucdavis.edu> */
+
+const char *ss;
+
+int __attribute__((noipa)) dummy (const char *s, ...)
+{
+  ss = s;
+}
+
+int i[6];
+static int j, v, e, f, h = 5, k, l, n, o, p, q, r, s, u, w, x, y, z, aa, ab, ac,
+                       ad, ae, af, ag = 8, ah, ai, aj, ak, al;
+char c;
+struct a {
+  unsigned b;
+  int c : 9;
+  int d;
+} static g = {9, 5};
+static short m[1], t = 95, am;
+int an, ao, ap;
+void aq(int ar) {
+  j = j & 5 ^ i[j ^ v & 5];
+  j = j & 5 ^ i[(j ^ v) & 5];
+  j = j & 4095 ^ (j ^ v) & 5;
+}
+void as(int ar) {
+  if (n)
+    s = 0;
+}
+static unsigned at() {
+  int au[] = {2080555007, 0};
+  for (; al; al--) {
+    if (r)
+      --x;
+    if (g.d)
+      l++;
+    dummy("", j);
+    if (u)
+      ae = n = au[al];
+  }
+  r = 0;
+  return 0;
+}
+int aw(int ar) {
+  int ax[] = {9, 5, 5, 9, 5}, ay = 3;
+  struct a az = {1, 3};
+av:
+  an = (as((at(), ax)[2]), ax[4]);
+  {
+    int ba[] = {5, 5, 9, 8, 1, 0, 5, 5, 9, 8, 1, 0,
+                5, 5, 9, 8, 1, 0, 5, 5, 9, 8, 1};
+    int a[] = {8, 2, 8, 2, 8, 2, 8};
+    int b[] = {1027239, 8, 1, 7, 9, 2, 9, 4, 4, 2, 8, 1, 0, 4, 4, 2,
+               4,       4, 2, 9, 2, 9, 8, 1, 7, 9, 2, 9, 4, 4, 2};
+    if (z) {
+      struct a bc;
+    bb:
+      for (; e; e++)
+        for (; q;)
+          return ax[e];
+      if (bc.c < g.d <= a[7])
+        aa--;
+    }
+    {
+      struct a bd = {5};
+      int d[20] = {1, 9, 7, 7, 8, 4, 4, 4, 4, 8, 1, 9, 7, 7, 8, 4, 4, 4, 4};
+      c = h | r % g.c ^ x;
+      dummy("", g);
+      am -= t | x;
+      if (h)
+        while (1) {
+          if (a[o]) {
+            struct a be;
+            if (ar) {
+              struct a bf = {908, 5, 3};
+              int bg[3], bh = k, bj = ag | ae, bk = aj + 3, bl = u << e;
+              if (f)
+                if (ac)
+                  ak = w;
+              ag = -(ag & t);
+              af = ag ^ af;
+              if (8 < af)
+                break;
+              if (bj)
+                goto bi;
+              if (s)
+                dummy("", 6);
+              be.d = k;
+              w = f - bh;
+              dummy("", be);
+              if (w)
+                goto bb;
+              ao = r - aa && g.b;
+              if (y)
+                k++;
+              goto av;
+            bi:
+              if (aa)
+                continue;
+              if (f)
+                if (k)
+                  dummy("", g);
+              aj = ac + k ^ g.c;
+              g.c = bk;
+              ah = 0;
+              for (; ah < 3; ah++)
+                if (s)
+                  bg[ah] = 8;
+              if (!ay)
+                dummy("", ai);
+              u = bl;
+              g = bf;
+            } else
+              for (;; o += a[ap])
+                ;
+            int bm[] = {0};
+            for (; p; p++)
+              c = ad;
+            ad = l;
+            if (bd.c) {
+              dummy(" ");
+              goto bi;
+            }
+          }
+          int bn[] = {5, 2, 2, 5, 2, 2, 5, 2, 2, 5, 2, 2, 5, 2, 2, 5,
+                      2, 2, 5, 2, 2, 5, 2, 2, 5, 2, 2, 5, 2, 2, 5, 2,
+                      2, 5, 2, 2, 5, 2, 2, 5, 2, 2, 5, 2, 2, 5, 2};
+          struct a a[] = {3440025416, 2, 8, 4, 2, 8, 4, 4, 2, 8, 4};
+          struct a b = {3075920};
+          if (f) {
+            aq(m[am + e]);
+            dummy("", j);
+            dummy("", e);
+            ab--;
+          }
+          if (ax[4]) {
+            if (l)
+              goto av;
+            ++f;
+          } else
+            ay = az.c && a;
+          for (; ac; ac++)
+            m[f] = 0;
+        }
+      h = 9;
+      for (; y; y = 1)
+        if (f)
+          goto av;
+    }
+  }
+  return 0;
+}
+
+int main (void)
+{
+  aw(1);
+  if (g.c!= 5)
+    __builtin_abort ();
+  return 0;
+}