PR tree-optimization/45903
* simplify-rtx.c (simplify_subreg): Optimize lowpart SUBREG
of *SHIFTRT of MEM.
* gcc.target/i386/pr45903.c: New test.
From-SVN: r165202
--- /dev/null
+/* PR tree-optimization/45903 */
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+unsigned long long a, b;
+unsigned char c;
+
+void
+f1 (void)
+{
+ c = (a >> 8) + (b >> 8);
+}
+
+void
+f2 (void)
+{
+ c = (a >> 8) | (b >> 8);
+}
+
+void
+f3 (void)
+{
+ c = (a >> 16) ^ (b >> 56);
+}
+
+unsigned char
+f4 (void)
+{
+ return (a >> 48) + (b >> 40);
+}
+
+unsigned char
+f5 (void)
+{
+ return (a >> 32) | (b >> 16);
+}
+
+unsigned char
+f6 (void)
+{
+ return (a >> 24) ^ (b >> 32);
+}
+
+/* { dg-final { scan-assembler-not "shr\[qdl\]" } } */