[PATCH][AArch64] Fix PR87511

[Wilco Dijkstra]

As mentioned in PR87511, the shift used in aarch64_mask_and_shift_for_ubfiz_p
should be evaluated as a HOST_WIDE_INT rather than int.

Passes bootstrap, OK for commit and backport?

ChangeLog:
2018-10-11  Wilco Dijkstra  <wdijk...@arm.com>

gcc/
        * config/aarch64/aarch64.c (aarch64_mask_and_shift_for_ubfiz_p):
        Use HOST_WIDE_INT_1U for shift.

testsuite/
        * gcc.target/aarch64/pr87511.c: Add new test.

--

diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 
385272b8867317be4b2d10e56da25af306121214..86cfb92861eda652718b4e0be013688718d8f1b2
 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -8549,7 +8549,8 @@ aarch64_mask_and_shift_for_ubfiz_p (scalar_int_mode mode, 
rtx mask,
   return CONST_INT_P (mask) && CONST_INT_P (shft_amnt)
         && INTVAL (shft_amnt) < GET_MODE_BITSIZE (mode)
         && exact_log2 ((INTVAL (mask) >> INTVAL (shft_amnt)) + 1) >= 0
-        && (INTVAL (mask) & ((1 << INTVAL (shft_amnt)) - 1)) == 0;
+        && (INTVAL (mask)
+            & ((HOST_WIDE_INT_1U << INTVAL (shft_amnt)) - 1)) == 0;
 }
 
 /* Calculate the cost of calculating X, storing it in *COST.  Result
diff --git a/gcc/testsuite/gcc.target/aarch64/pr87511.c 
b/gcc/testsuite/gcc.target/aarch64/pr87511.c
new file mode 100644
index 
0000000000000000000000000000000000000000..98064701594caefa747c10d87924746f295ad8cd
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/pr87511.c
@@ -0,0 +1,16 @@
+/* { dg-do assemble } */
+/* { dg-options "-Os" } */
+
+int a, d;
+struct {
+  signed f5 : 26;
+  signed f6 : 12;
+} b;
+signed char c;
+void fn1() {
+  signed char *e = &c;
+  d = a * 10;
+  *e = d;
+  b.f6 = c;
+  b.f5 = 8 <= 3;
+}