[PATCH], PR target/81348: Fix compiler segfault on -mcpu=power9 code

[Michael Meissner]

This patch fixes a typo where the wrong operand was used (a memory was used
where a register was intended), and the compiler segfaulted.

I did the bootstrap and make check with no regression on a little endian power8
system.  Can I install this in the trunk and the gcc 7.x branch (it isn't an
issue on the gcc 6.x branch)?

[gcc]
2017-07-07  Michael Meissner  <meiss...@linux.vnet.ibm.com>

        PR target/81348
        * config/rs6000/rs6000.md (HI sign_extend splitter): Use the
        correct operand in doing the split.

[gcc/testsuite]
2017-07-07  Michael Meissner  <meiss...@linux.vnet.ibm.com>

        PR target/81348
        * gcc.target/powerpc/pr81348.c: New test.

-- 
Michael Meissner, IBM
IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA
email: meiss...@linux.vnet.ibm.com, phone: +1 (978) 899-4797

Index: gcc/config/rs6000/rs6000.md
===================================================================
--- gcc/config/rs6000/rs6000.md (revision 250043)
+++ gcc/config/rs6000/rs6000.md (working copy)
@@ -940,7 +940,7 @@ (define_split
    (set (match_dup 0)
        (sign_extend:EXTHI (match_dup 2)))]
 {
-  operands[2] = gen_rtx_REG (HImode, REGNO (operands[1]));
+  operands[2] = gen_rtx_REG (HImode, REGNO (operands[0]));
 })
 
 (define_insn_and_split "*extendhi<mode>2_dot"
Index: gcc/testsuite/gcc.target/powerpc/pr81348.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/pr81348.c  (revision 0)
+++ gcc/testsuite/gcc.target/powerpc/pr81348.c  (working copy)
@@ -0,0 +1,24 @@
+/* { dg-do compile { target { powerpc64*-*-* && lp64 } } } */
+/* { dg-skip-if "do not override -mcpu" { powerpc*-*-* } { "-mcpu=*" } { 
"-mcpu=power9" } } */
+/* { dg-require-effective-target powerpc_p9vector_ok } */
+/* { dg-options "-mcpu=power9 -Og" } */
+
+/* PR target/81348: Compiler died in doing short->float conversion due to using
+   the wrong register in a define_split.  */
+
+int a;
+short b;
+float ***c;
+
+void d(void)
+{
+        int e = 3;
+
+        if (a)
+                e = b;
+
+        ***c = e;
+}
+
+/* { dg-final { scan-assembler {\mlxsihzx\M}  } } */
+/* { dg-final { scan-assembler {\mvextsh2d\M} } } */