[gcc/devel/omp/gcc-9] rs6000: Fix infinite loop building ghostscript and icu [PR93658]

[Tobias Burnus]

https://gcc.gnu.org/g:066184a282b622ac6880150eb4e42fe57881b606

commit 066184a282b622ac6880150eb4e42fe57881b606
Author: Peter Bergner <bergner@linux.ibm.com>
Date:   Sun Feb 23 18:22:57 2020 -0600

    rs6000: Fix infinite loop building ghostscript and icu [PR93658]
    
    Fix rs6000_legitimate_address_p(), which erroneously marks a valid Altivec
    address as being invalid, which causes LRA's process_address()  to go into
    an infinite loop spilling the same address over and over again.
    Include Mike's earlier commits that fix bugs this patch exposes.
    
    	Backport from master
    	2020-02-20  Peter Bergner  <bergner@linux.ibm.com>
    
    	PR target/93658
    	* config/rs6000/rs6000.c (rs6000_legitimate_address_p): Handle VSX
    	vector modes.
    
    	* gcc.target/powerpc/pr93658.c: New test.

Diff:
---
 gcc/ChangeLog                              |  9 +++++++++
 gcc/config/rs6000/rs6000.c                 |  2 +-
 gcc/testsuite/ChangeLog                    |  8 ++++++++
 gcc/testsuite/gcc.target/powerpc/pr93658.c | 20 ++++++++++++++++++++
 4 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ec6600a..8d8dbc0 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,6 +1,15 @@
 2020-02-23  Peter Bergner <bergner@linux.ibm.com>
 
 	Backport from master
+	2020-02-20  Peter Bergner  <bergner@linux.ibm.com>
+
+	PR target/93658
+	* config/rs6000/rs6000.c (rs6000_legitimate_address_p): Handle VSX
+	vector modes.
+
+2020-02-23  Peter Bergner <bergner@linux.ibm.com>
+
+	Backport from master
 	2020-02-05  Michael Meissner  <meissner@linux.ibm.com>
 
 	PR target/93568
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index ce1bd32..1d93570 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -9358,7 +9358,7 @@ rs6000_legitimate_address_p (machine_mode mode, rtx x, bool reg_ok_strict)
   bool quad_offset_p = mode_supports_dq_form (mode);
 
   /* If this is an unaligned stvx/ldvx type address, discard the outer AND.  */
-  if (VECTOR_MEM_ALTIVEC_P (mode)
+  if (VECTOR_MEM_ALTIVEC_OR_VSX_P (mode)
       && GET_CODE (x) == AND
       && CONST_INT_P (XEXP (x, 1))
       && INTVAL (XEXP (x, 1)) == -16)
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 9344d00..f02a941 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,11 @@
+2020-02-23  Peter Bergner  <bergner@linux.ibm.com>
+
+	Backport from master
+	2020-02-20  Peter Bergner  <bergner@linux.ibm.com>
+
+	PR target/93658
+	* gcc.target/powerpc/pr93658.c: New test.
+
 2020-02-20  H.J. Lu  <hongjiu.lu@intel.com>
 
 	Backport from master
diff --git a/gcc/testsuite/gcc.target/powerpc/pr93658.c b/gcc/testsuite/gcc.target/powerpc/pr93658.c
new file mode 100644
index 0000000..0170d34
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pr93658.c
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -fstack-protector-strong -mcpu=power8" } */
+/* { dg-require-effective-target powerpc_vsx_ok } */
+
+/* PR93658: Failure compiling this test is an infinite loop in LRA's
+   process_address(), so set a short timeout limit.  */
+/* { dg-timeout 5 } */
+
+void bar();
+char b;
+void
+foo (void)
+{
+  char a;
+  int d = b;
+  char *e = &a;
+  while (d)
+    *e++ = --d;
+  bar ();
+}