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Move call results out of %eax

--- a/6/insns.def

+++ b/6/insns.def

@@ -54,8 +54,8 @@

 Insn(Isetge,    "\tsetge %v\n",                 Use(),  Def(.l={1}))

 /* branch instructions */

-Insn(Icall,     "\tcall %v\n",                  Use(.l={1}), Def())

-Insn(Icallind,  "\tcall *%v\n",                 Use(.l={1}), Def())

+Insn(Icall,     "\tcall %v\n",                  Use(.l={1}), Def(.r={Rrax}))

+Insn(Icallind,  "\tcall *%v\n",                 Use(.l={1}), Def(.r={Rrax}))

 Insn(Ijmp,      "\tjmp %v\n",                   Use(.l={1}), Def())

 Insn(Ijz,       "\tjz %v\n",                    Use(.l={1}), Def())

 Insn(Ijnz,      "\tjnz %v\n",                   Use(.l={1}), Def())

--- a/6/isel.c

+++ b/6/isel.c

@@ -358,19 +358,23 @@

 static Loc *gencall(Isel *s, Node *n)

 {

-    Loc *src, *dst, *arg, *fn;   /* values we reduced */

-    Loc *rax, *rsp;       /* hard-coded registers */

+    Loc *src, *dst, *arg, *fn;  /* values we reduced */

+    Loc *rax, *rsp, *ret;       /* hard-coded registers */

     Loc *stkbump;        /* calculated stack offset */

     int argsz, argoff;

     size_t i;

     rsp = locphysreg(Rrsp);

-    if (tybase(exprtype(n))->type == Tyvoid)

+    if (tybase(exprtype(n))->type == Tyvoid) {

         rax = NULL;

-    else if (stacktype(exprtype(n)))

+        ret = NULL;

+    } else if (stacktype(exprtype(n))) {

         rax = locphysreg(Rrax);

-    else

+        ret = locreg(ModeQ);

+    } else {

         rax = coreg(Rrax, mode(n));

+        ret = locreg(mode(n));

+    }

     argsz = 0;

     /* Have to calculate the amount to bump the stack

      * pointer by in one pass first, otherwise if we push

@@ -407,7 +411,9 @@

         g(s, Icallind, fn, NULL);

     if (argsz)

         g(s, Iadd, stkbump, rsp, NULL);

-    return rax;

+    if (rax)

+        g(s, Imov, rax, ret, NULL);

+    return ret;

 }

 Loc *selexpr(Isel *s, Node *n)

@@ -572,6 +578,7 @@

             break;

         case Otrunc:

             a = selexpr(s, args[0]);

+            a = inr(s, a);

             r = locreg(mode(n));

             g(s, Imov, a, r, NULL);

             break;

@@ -892,6 +899,10 @@

     is.globls = globls;

     is.ret = fn->ret;

     is.cfg = fn->cfg;

+    /* ensure that all physical registers have a loc created, so we

+     * don't get any surprises referring to them in the allocator */

+    for (i = 0; i < Nreg; i++)

+        locphysreg(i);

     for (i = 0; i < fn->cfg->nbb; i++)

         lappend(&is.bb, &is.nbb, mkasmbb(fn->cfg->bb[i]));

--- a/6/ra.c

+++ b/6/ra.c

@@ -559,6 +559,11 @@

 {

     regid t;

+    /* Regs of different modes can't be combined as things stand.

+     * In principle they should be combinable, but it confused the

+     * whole mode dance. */

+    if (locmap[u]->mode != locmap[v]->mode)

+        return 0;

     /* if u isn't prepainted, can we conservatively coalesce? */

     if (!bshas(s->prepainted, u) && conservative(s, u, v))

         return 1;