[arm] PR target/82975: Guard against reg_renumber being NULL in arm.h

In this bug we ICE when checking REGNO_OK_FOR_INDEX_P on arm during pre-IRA scheduling.
This is because REGNO_OK_FOR_INDEX_P ends up checking the reg_renumber array.
Before IRA reg_renumber is NULL and thus we segfault.

The fix is to guard the use of reg_renumber in the logic in TEST_REGNO in arm.h.
On aarch64, for example, we also guard against the reg_renumber == NULL case.
This fixes the ICE. I also remove the part of the comment that muses on when reg_renumber
is available as with this patch it should now be safe to use at any point.

Bootstrapped and tested on arm-none-linux-gnueabihf.

	PR target/82975
	* config/arm/arm.h (TEST_REGNO): Check reg_renumber is set before
	accessing it.  Adjust comment.

	* gcc.dg/pr82975.c: New test.

From-SVN: r255830

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 31277b9a9f45af94cb397cc9d650d7a4824e43f2..76dbd695718ad47d9127d8f38bae375767c479f2 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,4 +1,10 @@
-2017-12-18  Jakub Jelinek  <jakub@redhat.com>
+2017-12-19  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+       PR target/82975
+       * config/arm/arm.h (TEST_REGNO): Check reg_renumber is set before
+       accessing it.  Adjust comment.
+
+2017-12-19  Jakub Jelinek  <jakub@redhat.com>
 
        PR middle-end/81914
        * predict.c (zero_one_minusone): New function.

diff --git a/gcc/config/arm/arm.h b/gcc/config/arm/arm.h
index ac51412fe453bf28a09b3754c3d0b2d4db603412..a482f0342a9f793ec7fd0dc6eb89e29f422c443f 100644 (file)
--- a/gcc/config/arm/arm.h
+++ b/gcc/config/arm/arm.h
@@ -1620,7 +1620,8 @@ enum arm_auto_incmodes
    has been allocated, which happens in reginfo.c during register
    allocation.  */
 #define TEST_REGNO(R, TEST, VALUE) \
-  ((R TEST VALUE) || ((unsigned) reg_renumber[R] TEST VALUE))
+  ((R TEST VALUE)      \
+    || (reg_renumber && ((unsigned) reg_renumber[R] TEST VALUE)))
 
 /* Don't allow the pc to be used.  */
 #define ARM_REGNO_OK_FOR_BASE_P(REGNO)                 \

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 200a813ca6cd75ae976dfd05adab740afa327067..e0eb513f07f48510b3db38e48818b26781b8d04f 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2017-12-19  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+       PR target/82975
+       * gcc.dg/pr82975.c: New test.
+
 2017-12-19  Marek Polacek  <polacek@redhat.com>
 
        PR c++/83489

diff --git a/gcc/testsuite/gcc.dg/pr82975.c b/gcc/testsuite/gcc.dg/pr82975.c
new file mode 100644 (file)
index 0000000..e6c13bc
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr82975.c
@@ -0,0 +1,19 @@
+/* PR target/82975.  */
+/* { dg-do compile } */
+/* { dg-options "-mtune=cortex-a57 -fno-sched-pressure -O2" } */
+
+typedef __SIZE_TYPE__ size_t;
+
+struct S1
+{
+  char pad1;
+  char val;
+  short pad2;
+};
+
+extern char t[256];
+
+void foo (struct S1 a, size_t i)
+{
+  t[i] = a.val;
+}