[PATCH] rs6000: Fix split of ashdi3_extswsli_dot for memory (PR71670)

[Segher Boessenkool]

The splitter for ashdi3_extswsli_dot for cr0 with memory uses emit_insn
gen_ashdi3_extswsli_dot, which does not work because that emits a scratch,
while the splitter runs after reload so there should be a real register
instead.  We can laboriously fix that up, or emit using
gen_ashdi3_extswsli_dot2 instead.  This patch does the latter.

Tested that the new testcase fails without, and works with the patch.
Now bootstrapping.


Segher


2016-06-27  Segher Boessenkool  <seg...@kernel.crashing.org>

        PR target/71670
        * config/rs6000/rs6000.md (ashdi3_extswsli_dot): Use
        gen_ashdi3_extswsli_dot2 instead of gen_ashdi3_extswsli_dot.

gcc/testsuite/
        PR target/71670
        * gcc.target/powerpc/pr71670.c: New testcase.

---
 gcc/config/rs6000/rs6000.md                | 2 +-
 gcc/testsuite/gcc.target/powerpc/pr71670.c | 7 +++++++
 2 files changed, 8 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gcc.target/powerpc/pr71670.c

diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md
index 133eef1..39a9cf8 100644
--- a/gcc/config/rs6000/rs6000.md
+++ b/gcc/config/rs6000/rs6000.md
@@ -4087,7 +4087,7 @@ (define_insn_and_split "ashdi3_extswsli_dot"
 
   if (REGNO (cr) == CR0_REGNO)
     {
-      emit_insn (gen_ashdi3_extswsli_dot (dest, src2, shift, cr));
+      emit_insn (gen_ashdi3_extswsli_dot2 (dest, src2, shift, cr));
       DONE;
     }
 
diff --git a/gcc/testsuite/gcc.target/powerpc/pr71670.c 
b/gcc/testsuite/gcc.target/powerpc/pr71670.c
new file mode 100644
index 0000000..18fb627
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pr71670.c
@@ -0,0 +1,7 @@
+/* { dg-do compile { target { powerpc*-*-* } } } */
+/* { dg-skip-if "do not override -mcpu" { powerpc*-*-* } { "-mcpu=*" } { 
"-mcpu=power9" } } */
+/* { dg-options "-mcpu=power9 -O1" } */
+
+volatile int a;
+int b;
+void fn1(void) { b + (long)b || a; }
-- 
1.9.3