MIPS: Don't use argument GPRs to rematerialize FPR arguments.

1 files changed, 20 insertions, 11 deletions

diff --git a/src/lj_asm_mips.h b/src/lj_asm_mips.h
index 299b4439..14ebd1b3 100644
--- a/src/lj_asm_mips.h
+++ b/src/lj_asm_mips.h
@@ -227,9 +227,12 @@ static void asm_gencall(ASMState *as, const CCallInfo *ci, IRRef *args)
 {
   uint32_t n, nargs = CCI_NARGS(ci);
   int32_t ofs = 16;
-  Reg gpr = REGARG_FIRSTGPR, fpr = REGARG_FIRSTFPR;
+  Reg gpr, fpr = REGARG_FIRSTFPR;
   if ((void *)ci->func)
     emit_call(as, (void *)ci->func);
+  for (gpr = REGARG_FIRSTGPR; gpr <= REGARG_LASTGPR; gpr++)
+    as->cost[gpr] = REGCOST(~0u, 0u);
+  gpr = REGARG_FIRSTGPR;
   for (n = 0; n < nargs; n++) {  /* Setup args. */
     IRRef ref = args[n];
     if (ref) {
@@ -245,16 +248,22 @@ static void asm_gencall(ASMState *as, const CCallInfo *ci, IRRef *args)
         if (irt_isnum(ir->t)) gpr = (gpr+1) & ~1;
         if (gpr <= REGARG_LASTGPR) {
           lua_assert(rset_test(as->freeset, gpr));  /* Already evicted. */
-          if (irt_isnum(ir->t)) {
-            Reg r = ra_alloc1(as, ref, RSET_FPR);
-            emit_tg(as, MIPSI_MFC1, gpr+(LJ_BE?0:1), r+1);
-            emit_tg(as, MIPSI_MFC1, gpr+(LJ_BE?1:0), r);
-            lua_assert(rset_test(as->freeset, gpr+1));  /* Already evicted. */
-            gpr += 2;
-          } else if (irt_isfloat(ir->t)) {
-            Reg r = ra_alloc1(as, ref, RSET_FPR);
-            emit_tg(as, MIPSI_MFC1, gpr, r);
-            gpr++;
+          if (irt_isfp(ir->t)) {
+            RegSet of = as->freeset;
+            Reg r;
+            /* Workaround to protect argument GPRs from being used for remat. */
+            as->freeset &= ~RSET_RANGE(REGARG_FIRSTGPR, REGARG_LASTGPR+1);
+            r = ra_alloc1(as, ref, RSET_FPR);
+            as->freeset |= (of & RSET_RANGE(REGARG_FIRSTGPR, REGARG_LASTGPR+1));
+            if (irt_isnum(ir->t)) {
+              emit_tg(as, MIPSI_MFC1, gpr+(LJ_BE?0:1), r+1);
+              emit_tg(as, MIPSI_MFC1, gpr+(LJ_BE?1:0), r);
+              lua_assert(rset_test(as->freeset, gpr+1));  /* Already evicted. */
+              gpr += 2;
+            } else if (irt_isfloat(ir->t)) {
+              emit_tg(as, MIPSI_MFC1, gpr, r);
+              gpr++;
+            }
           } else {
             ra_leftov(as, gpr, ref);
             gpr++;