[PATCH][MIPS] Fix ICE in bitmap routines with LRA and inline assembly language

[Robert Suchanek]

Hi, 

Following up the problem reported
https://gcc.gnu.org/ml/gcc/2014-09/msg00094.html

I am attaching the patch fixing the internal compiler error.

The problem appeared to be that the current program point was not
incremented after changing liveliness of a pseudo. In the attached testcase,
an early clobber pseudo register became dead but the result was overwritten 
by subsequent calls to mark_regno_dead function returning false. As a result, 
the live range of the pseudo was 0..1 but the lra_live_max_point was not 
+1 higher leading to lack of initialization of internal structures and 
processing random data, hence, the ICE.

The patch was bootstrapped and regtested on x86_64-unknown-linux-gnu.

Regards,
Robert

2014-09-09  Robert Suchanek  <robert.sucha...@imgtec.com>

gcc/
        * lra-lives.c (process_bb_lives): Replace assignment with bitwise OR
        assignment.

gcc/testsuite/
        * gcc.target/mips/20140909.c: New test.
---
 gcc/lra-lives.c                          |    6 +++---
 gcc/testsuite/gcc.target/mips/20140909.c |   20 ++++++++++++++++++++
 2 files changed, 23 insertions(+), 3 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/mips/20140909.c

diff --git a/gcc/lra-lives.c b/gcc/lra-lives.c
index f34517d..b72824e 100644
--- a/gcc/lra-lives.c
+++ b/gcc/lra-lives.c
@@ -680,9 +680,9 @@ process_bb_lives (basic_block bb, int &curr_point)
       /* Mark early clobber outputs dead.  */
       for (reg = curr_id->regs; reg != NULL; reg = reg->next)
        if (reg->type == OP_OUT && reg->early_clobber && ! reg->subreg_p)
-         need_curr_point_incr = mark_regno_dead (reg->regno,
-                                                 reg->biggest_mode,
-                                                 curr_point);
+         need_curr_point_incr |= mark_regno_dead (reg->regno,
+                                                  reg->biggest_mode,
+                                                  curr_point);
 
       for (reg = curr_static_id->hard_regs; reg != NULL; reg = reg->next)
        if (reg->type == OP_OUT && reg->early_clobber && ! reg->subreg_p)
diff --git a/gcc/testsuite/gcc.target/mips/20140909.c 
b/gcc/testsuite/gcc.target/mips/20140909.c
new file mode 100644
index 0000000..dbdfb30
--- /dev/null
+++ b/gcc/testsuite/gcc.target/mips/20140909.c
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-skip-if "code quality test" { *-*-* } { "-O0" } { "" } } */ 
+
+NOMIPS16 int NoBarrier_AtomicIncrement(volatile int* ptr, int increment) {
+  int temp, temp2;
+  __asm__ __volatile__(".set push\n"
+                       ".set noreorder\n"
+                       "1:\n"
+                       "ll %0, 0(%3)\n"
+                       "addu %1, %0, %2\n"
+                       "sc %1, 0(%3)\n"
+                       "beqz %1, 1b\n"
+                       "addu %1, %0, %2\n"
+                       ".set pop\n"
+                       : "=&r" (temp), "=&r" (temp2)
+                       : "Ir" (increment), "r" (ptr)
+                       : "memory");
+
+  return temp2;
+}
-- 
1.7.9.5