two gcc mpc8548 crashes

[Eliot Dresselhaus]

I think I may have found 2 crashes with gcc-4.1.0 ppc-linux

ppc-linux-gcc -O2 -mcpu=8548 -mfloat-gprs=double -c [xy].c

Crash 1) x.c:

    double f (void) { return 0; }

I get an unrecognizable insn.  Here's a fix that works for me; I'm not
completely sure about it.  Can someone comment?

--- /home/eliot/gcc/gcc/config/rs6000/spe.md    2006-04-20 
11:04:24.000000000 -0700
+++ /home/eliot/teak/gcc/gcc/config/rs6000/spe.md    2006-04-20 
17:18:10.000000000 -0700
@@ -2211,11 +2211,13 @@
   [(set_attr "length" "8")])
 
 (define_insn "*frob_di_df_2"
-  [(set (subreg:DF (match_operand:DI 0 "register_operand" "=&r") 0)
-    (match_operand:DF 1 "register_operand" "r"))]
+  [(set (subreg:DF (match_operand:DI 0 "register_operand" "=&r,r") 0)
+    (match_operand:DF 1 "input_operand" "r,m"))]
   "TARGET_E500_DOUBLE"
-  "evmergehi %H0,%1,%1\;evmergelo %L0,%1,%1"
-  [(set_attr "length" "8")])
+  "@
+   evmergehi %H0,%1,%1\;evmergelo %L0,%1,%1
+   evldd%X1 %0,%y1"
+  [(set_attr "length" "8,4")])
 
 (define_insn "*mov_sidf_e500_subreg0"
   [(set (subreg:SI (match_operand:DF 0 "register_operand" "+r") 0)

Crash 2) y.c from glibc-2.4.

static const int init_jk[] = {2,3,4,6}; /* initial value for jk */

static const double PIo2[] = {
  1.57079625129699707031e+00, /* 0x3FF921FB, 0x40000000 */
  7.54978941586159635335e-08, /* 0x3E74442D, 0x00000000 */
  5.39030252995776476554e-15, /* 0x3CF84698, 0x80000000 */
  3.28200341580791294123e-22, /* 0x3B78CC51, 0x60000000 */
  1.27065575308067607349e-29, /* 0x39F01B83, 0x80000000 */
  1.22933308981111328932e-36, /* 0x387A2520, 0x40000000 */
  2.73370053816464559624e-44, /* 0x36E38222, 0x80000000 */
  2.16741683877804819444e-51, /* 0x3569F31D, 0x00000000 */
};

static const double
zero   = 0.0,
one    = 1.0,
two24   =  1.67772160000000000000e+07, /* 0x41700000, 0x00000000 */
twon24  =  5.96046447753906250000e-08; /* 0x3E700000, 0x00000000 */

typedef int int32_t;

int __kernel_rem_pio2(double *x, double *y, int e0, int nx, int prec, 
const int32_t *ipio2)
{
    int32_t jz,jx,jv,jp,jk,carry,n,iq[20],i,j,k,m,q0,ih;
    double z,fw,f[20],fq[20],q[20];

    /* initialize jk*/
    jk = init_jk[prec];
    jp = jk;

    /* determine jx,jv,q0, note that 3>q0 */
    jx =  nx-1;
    jv = (e0-3)/24; if(jv<0) jv=0;
    q0 =  e0-24*(jv+1);

    /* set up f[0] to f[jx+jk] where f[jx+jk] = ipio2[jv+jk] */
    j = jv-jx; m = jx+jk;
    for(i=0;i<=m;i++,j++) f[i] = (j<0)? zero : (double) ipio2[j];

    /* compute q[0],q[1],...q[jk] */
    for (i=0;i<=jk;i++) {
        for(j=0,fw=0.0;j<=jx;j++) fw += x[j]*f[jx+i-j]; q[i] = fw;
    }

    jz = jk;
recompute:

    /* compute n */
    z  = 0;
    n  = (int32_t) z;
    z -= (double)n;
    ih = 0;
    if(q0>0) {    /* need iq[jz-1] to determine n */
        i  = (iq[jz-1]>>(24-q0)); n += i;
        iq[jz-1] -= i<<(24-q0);
        ih = iq[jz-1]>>(23-q0);
    }
    else if(q0==0) ih = iq[jz-1]>>23;
    else if(z>=0.5) ih=2;

    if(ih>0) {    /* q > 0.5 */
        n += 1; carry = 0;
        for(i=0;i<jz ;i++) {    /* compute 1-q */
        j = iq[i];
        if(carry==0) {
            if(j!=0) {
            carry = 1; iq[i] = 0x1000000- j;
            }
        } else  iq[i] = 0xffffff - j;
        }
        if(q0>0) {        /* rare case: chance is 1 in 12 */
            switch(q0) {
            case 1:
               iq[jz-1] &= 0x7fffff; break;
            case 2:
               iq[jz-1] &= 0x3fffff; break;
            }
        }
        if(ih==2) {
        z = one - z;
        if(carry!=0) z = 0;
        }
    }

    /* check if recomputation is needed */
    if(z==zero) {
        j = 0;
        for (i=jz-1;i>=jk;i--) j |= iq[i];
        if(j==0) { /* need recomputation */
        for(k=1;iq[jk-k]==0;k++);   /* k = no. of terms needed */

        for(i=jz+1;i<=jz+k;i++) {   /* add q[jz+1] to q[jz+k] */
            f[jx+i] = (double) ipio2[jv+i];
            for(j=0,fw=0.0;j<=jx;j++) fw += x[j]*f[jx+i-j];
            q[i] = fw;
        }
        jz += k;
        goto recompute;
        }
    }

    /* compute PIo2[0,...,jp]*q[jz,...,0] */
    for(i=jz;i>=0;i--) {
        for(fw=0.0,k=0;k<=jp&&k<=jz-i;k++) fw += PIo2[k]*q[i+k];
        fq[jz-i] = fw;
    }

    /* compress fq[] into y[] */
    switch(prec) {
        case 0:
        fw = 0.0;
        for (i=jz;i>=0;i--) fw += fq[i];
        y[0] = (ih==0)? fw: -fw;
        break;
        case 1:
        case 2:
        fw = 0.0;
        for (i=jz;i>=0;i--) fw += fq[i];
        y[0] = (ih==0)? fw: -fw;
        fw = fq[0]-fw;
        for (i=1;i<=jz;i++) fw += fq[i];
        y[1] = (ih==0)? fw: -fw;
        break;
        case 3:    /* painful */
        for (i=jz;i>0;i--) {
            fw      = fq[i-1]+fq[i];
            fq[i]  += fq[i-1]-fw;
            fq[i-1] = fw;
        }
        for (i=jz;i>1;i--) {
            fw      = fq[i-1]+fq[i];
            fq[i]  += fq[i-1]-fw;
            fq[i-1] = fw;
        }
        for (fw=0.0,i=jz;i>=2;i--) fw += fq[i];
        if(ih==0) {
            y[0] =  fq[0]; y[1] =  fq[1]; y[2] =  fw;
        } else {
            y[0] = -fq[0]; y[1] = -fq[1]; y[2] = -fw;
        }
    }
    return n&7;
}