From 2cdf90f0683e4da3afc8554d17859260fdc6b4dc Mon Sep 17 00:00:00 2001
From: Mike Pall <mike>
Date: Tue, 23 Apr 2013 00:08:04 +0200
Subject: [PATCH] Always emit TOSTR for non-string CAT operands. Fuse in
 backend.

---
 src/lj_asm.c      | 30 +++++++++++++++++-------------
 src/lj_opt_fold.c | 28 ++++++++++++----------------
 src/lj_record.c   |  9 ++++++---
 3 files changed, 35 insertions(+), 32 deletions(-)

diff --git a/src/lj_asm.c b/src/lj_asm.c
index 7ebde7b8..a550d3b3 100644
--- a/src/lj_asm.c
+++ b/src/lj_asm.c
@@ -1057,26 +1057,30 @@ static void asm_bufhdr(ASMState *as, IRIns *ir)
 
 static void asm_bufput(ASMState *as, IRIns *ir)
 {
-  const CCallInfo *ci;
+  const CCallInfo *ci = &lj_ir_callinfo[IRCALL_lj_buf_putstr];
   IRRef args[2];
-  IRIns *ir2;
+  IRIns *irs;
   if (!ra_used(ir)) return;
   args[0] = ir->op1;  /* SBuf * */
-  args[1] = ir->op2;  /* int, double, GCstr * */
-  ir2 = IR(ir->op2);
-  if (irt_isstr(ir2->t)) {
-    ci = &lj_ir_callinfo[IRCALL_lj_buf_putstr];
-  } else if (LJ_SOFTFP ? irt_type((ir2+1)->t)==IRT_SOFTFP : irt_isnum(ir2->t)) {
-    ci = &lj_ir_callinfo[IRCALL_lj_buf_putnum];
-    args[1] = ASMREF_TMP1;
-  } else {
-    lua_assert(irt_isinteger(ir2->t));
-    ci = &lj_ir_callinfo[IRCALL_lj_buf_putint];
+  args[1] = ir->op2;  /* GCstr * */
+  irs = IR(ir->op2);
+  lua_assert(irt_isstr(irs->t));
+  if (mayfuse(as, ir->op2) && ra_noreg(irs->r)) {
+    if (irs->o == IR_TOSTR) {  /* Fuse number to string conversions. */
+      if (LJ_SOFTFP ? (irs+1)->o == IR_HIOP : irt_isnum(IR(irs->op1)->t)) {
+	ci = &lj_ir_callinfo[IRCALL_lj_buf_putnum];
+	args[1] = ASMREF_TMP1;  /* TValue * */
+      } else {
+	lua_assert(irt_isinteger(IR(irs->op1)->t));
+	ci = &lj_ir_callinfo[IRCALL_lj_buf_putint];
+	args[1] = irs->op1;  /* int */
+      }
+    }
   }
   asm_setupresult(as, ir, ci);  /* SBuf * */
   asm_gencall(as, ci, args);
   if (args[1] == ASMREF_TMP1)
-    asm_tvptr(as, ra_releasetmp(as, ASMREF_TMP1), ir->op2);
+    asm_tvptr(as, ra_releasetmp(as, ASMREF_TMP1), irs->op1);
 }
 
 static void asm_bufstr(ASMState *as, IRIns *ir)
diff --git a/src/lj_opt_fold.c b/src/lj_opt_fold.c
index fc91a75e..e3194f76 100644
--- a/src/lj_opt_fold.c
+++ b/src/lj_opt_fold.c
@@ -541,13 +541,13 @@ LJFOLDF(bufput_append)
 LJFOLD(BUFPUT any any)
 LJFOLDF(bufput_kgc)
 {
-  if (fright->o == IR_KGC) {
+  if (LJ_LIKELY(J->flags & JIT_F_OPT_FOLD) && fright->o == IR_KGC) {
     GCstr *s2 = ir_kstr(fright);
     MSize len2 = s2->len;
     if (len2 == 0) {  /* Empty string? */
       return LEFTFOLD;
     } else {
-      if (fleft->o == IR_BUFPUT && IR(fleft->op2)->o == IR_KGC &&
+      if (fleft->o == IR_BUFPUT && irref_isk(fleft->op2) &&
 	  !irt_isphi(fleft->t)) {
 	/* Join two constant string puts in a row. */
 	GCstr *s1 = ir_kstr(IR(fleft->op2));
@@ -570,20 +570,16 @@ LJFOLD(BUFSTR any any)
 LJFOLDF(bufstr_kfold_cse)
 {
   lua_assert(fright->o == IR_BUFHDR || fright->o == IR_BUFPUT);
-  if (fright->o == IR_BUFHDR) {  /* No put operations? */
-    if (!(fright->op2 & IRBUFHDR_APPEND))  /* Empty buffer? */
-      return lj_ir_kstr(J, &J2G(J)->strempty);
-    fins->op2 = fright->prev;  /* Relies on checks in bufput_append. */
-    return CSEFOLD;
-  } else {
-    /* Shortcut for a single put operation. */
-    IRIns *irb = IR(fright->op1);
-    if (irb->o == IR_BUFHDR && !(irb->op2 & IRBUFHDR_APPEND)) {
-      IRRef ref = fright->op2;
-      if (irt_isstr(IR(ref)->t))
-	return ref;
-      lua_assert(irt_isinteger(IR(ref)->t) || irt_isnum(IR(ref)->t));
-      return emitir(IRT(IR_TOSTR, IRT_STR), ref, 0);
+  if (LJ_LIKELY(J->flags & JIT_F_OPT_FOLD)) {
+    if (fright->o == IR_BUFHDR) {  /* No put operations? */
+      if (!(fright->op2 & IRBUFHDR_APPEND))  /* Empty buffer? */
+	return lj_ir_kstr(J, &J2G(J)->strempty);
+      fins->op2 = fright->prev;  /* Relies on checks in bufput_append. */
+      return CSEFOLD;
+    } else {
+      IRIns *irb = IR(fright->op1);
+      if (irb->o == IR_BUFHDR && !(irb->op2 & IRBUFHDR_APPEND))
+	return fright->op2;  /* Shortcut for a single put operation. */
     }
   }
   /* Try to CSE the whole chain. */
diff --git a/src/lj_record.c b/src/lj_record.c
index bbabd3ce..bafb6ff7 100644
--- a/src/lj_record.c
+++ b/src/lj_record.c
@@ -1608,10 +1608,13 @@ static TRef rec_cat(jit_State *J, BCReg baseslot, BCReg topslot)
   lua_assert(baseslot < topslot);
   if (tref_isnumber_str(tr) && tref_isnumber_str(*(top-1))) {
     TRef hdr, *trp, *xbase, *base = &J->base[baseslot];
-    /* First convert number consts to string consts to simplify FOLD rules. */
-    for (trp = top; trp >= base && tref_isnumber_str(*trp); trp--)
-      if (tref_isk(*trp) && tref_isnumber(*trp))
+    /* First convert numbers to strings. */
+    for (trp = top; trp >= base; trp--) {
+      if (tref_isnumber(*trp))
 	*trp = emitir(IRT(IR_TOSTR, IRT_STR), *trp, 0);
+      else if (!tref_isstr(*trp))
+	break;
+    }
     xbase = ++trp;
     tr = hdr = emitir(IRT(IR_BUFHDR, IRT_P32),
 		      lj_ir_kptr(J, &J2G(J)->tmpbuf), IRBUFHDR_RESET);