Commit ecbb5ea1 authored by Aurelien Jarno's avatar Aurelien Jarno
Browse files

target-alpha: overflow condition for sublv and subqv 



The conditions to detect overflow in sub operations was wrong.

This patch is necessary to boot Tru64.

Signed-off-by: default avatarTristan Gingold <gingold@adacore.com>
Signed-off-by: default avatarAurelien Jarno <aurelien@aurel32.net>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@7073 c046a42c-6fe2-441c-8c8c-71466251a162
parent 68238a9e

target-alpha/op_helper.c

+8 −8
Original line number Diff line number Diff line
@@ -158,22 +158,22 @@ uint64_t helper_addlv (uint64_t op1, uint64_t op2) 


uint64_t helper_subqv (uint64_t op1, uint64_t op2)

{

    uint64_t tmp = op1;

    op1 -= op2;

    if (unlikely(((~tmp) ^ op1 ^ (-1ULL)) & ((~tmp) ^ op2) & (1ULL << 63))) {

    uint64_t res;

    res = op1 - op2;

    if (unlikely((op1 ^ op2) & (res ^ op1) & (1ULL << 63))) {

        helper_excp(EXCP_ARITH, EXCP_ARITH_OVERFLOW);

    }

    return op1;

    return res;

}



uint64_t helper_sublv (uint64_t op1, uint64_t op2)

{

    uint64_t tmp = op1;

    op1 = (uint32_t)(op1 - op2);

    if (unlikely(((~tmp) ^ op1 ^ (-1UL)) & ((~tmp) ^ op2) & (1UL << 31))) {

    uint32_t res;

    res = op1 - op2;

    if (unlikely((op1 ^ op2) & (res ^ op1) & (1UL << 31))) {

        helper_excp(EXCP_ARITH, EXCP_ARITH_OVERFLOW);

    }

    return op1;

    return res;

}



uint64_t helper_mullv (uint64_t op1, uint64_t op2)

tests/alpha/Makefile

+3 −0
Original line number Diff line number Diff line
@@ -23,6 +23,9 @@ test-cmov.o: test-cond.c 
test-cmov: test-cmov.o crt.o

	$(LINK)



test-ovf: test-ovf.o crt.o

	$(LINK)



check: $(TESTS)

	for f in $(TESTS); do $(SIM) $$f || exit 1; done

tests/alpha/test-ovf.c

0 → 100644
+29 −0
Original line number Diff line number Diff line 
static long test_subqv (long a, long b)

{

  long res;



  asm ("subq/v %1,%2,%0"

       : "=r" (res) : "r" (a), "r" (b));

  return res;

}

static struct {

  long (*func)(long, long);

  long a;

  long b;

  long r;

} vectors[] =

  {

    {test_subqv, 0, 0x7d54000, 0xfffffffff82ac000L}

  };



int main (void)

{

  int i;



  for (i = 0; i < sizeof (vectors)/sizeof(vectors[0]); i++)

    if ((*vectors[i].func)(vectors[i].a, vectors[i].b) != vectors[i].r) {

      write(1, "Failed\n", 7);

    }

  write(1, "OK\n", 3);

  return 0;

}