LRA: Check input insn pattern hard regs against early clobber hard regs for live...

For the test case LRA generates wrong code for AVR cpymem_qi insn:

	(insn 16 15 17 3 (parallel [
            (set (mem:BLK (reg:HI 26 r26) [0  A8])
                (mem:BLK (reg:HI 30 r30) [0  A8]))
            (unspec [
                    (const_int 0 [0])
                ] UNSPEC_CPYMEM)
            (use (reg:QI 52))
            (clobber (reg:HI 26 r26))
            (clobber (reg:HI 30 r30))
            (clobber (reg:QI 0 r0))
            (clobber (reg:QI 52))
        ]) "t.c":16:22 132 {cpymem_qi}

The insn gets the same value in r26 and r30.  The culprit is clobbering
r30 and using r30 as input.  For such situation LRA wrongly assumes that
r30 does not live before the insn.  The patch is fixing it.

gcc/ChangeLog:

	* lra-lives.cc (process_bb_lives): Check input insn pattern hard regs
	against early clobber hard regs.

gcc/testsuite/ChangeLog:

	* gcc.target/avr/lra-cpymem_qi.c: New.

diff --git a/gcc/lra-lives.cc b/gcc/lra-lives.cc
index f7a3ba8d76a3120164d93c92cd1ee1ba320c1469..f60e564da82fa864fe0f65e55cb3d8f1f85dfca4 100644 (file)
--- a/gcc/lra-lives.cc
+++ b/gcc/lra-lives.cc
@@ -989,7 +989,7 @@ process_bb_lives (basic_block bb, int &curr_point, bool dead_insn_p)
            /* We can have early clobbered non-operand hard reg and
               the same hard reg as an insn input.  Don't make hard
               reg dead before the insns.  */
-           for (reg2 = curr_id->regs; reg2 != NULL; reg2 = reg2->next)
+           for (reg2 = curr_static_id->hard_regs; reg2 != NULL; reg2 = reg2->next)
              if (reg2->type != OP_OUT && reg2->regno == reg->regno)
                break;
            if (reg2 == NULL)

diff --git a/gcc/testsuite/gcc.target/avr/lra-cpymem_qi.c b/gcc/testsuite/gcc.target/avr/lra-cpymem_qi.c
new file mode 100644 (file)
index 0000000..fdffb44
--- /dev/null
+++ b/gcc/testsuite/gcc.target/avr/lra-cpymem_qi.c
@@ -0,0 +1,26 @@
+/* { dg-do compile } */
+/* { dg-options "-mmcu=avr51 -Os" } */
+
+#include <stdbool.h>
+
+struct A
+{
+  unsigned int a;
+  unsigned char c1, c2;
+  bool b1 : 1;
+};
+
+void
+foo (const struct A *x, int y)
+{
+  int s = 0, i;
+  for (i = 0; i < y; ++i)
+    {
+      const struct A a = x[i];
+      s += a.b1 ? 1 : 0;
+    }
+  if (s != 0)
+    __builtin_abort ();
+}
+
+/* { dg-final { scan-assembler-not "movw\[^\n\r]*r26,r30" } } */