From fd63b05253f11d7e436c3685827fce9b64725da6 Mon Sep 17 00:00:00 2001
From: Mike Pall <mike>
Date: Thu, 9 Sep 2010 12:01:29 +0200
Subject: [PATCH] Use biased integer constant for TSETM array index.

---
 lib/bc.lua           |  4 +++-
 src/buildvm_x86.dasc | 12 ++----------
 src/lj_parse.c       |  3 ++-
 3 files changed, 7 insertions(+), 12 deletions(-)

diff --git a/lib/bc.lua b/lib/bc.lua
index 51fc1bd0..78b342f2 100644
--- a/lib/bc.lua
+++ b/lib/bc.lua
@@ -70,8 +70,9 @@ local function bcline(func, pc, prefix)
   local ma, mb, mc = band(m, 7), band(m, 15*8), band(m, 15*128)
   local a = band(shr(ins, 8), 0xff)
   local oidx = 6*band(ins, 0xff)
+  local op = sub(bcnames, oidx+1, oidx+6)
   local s = format("%04d %s %-6s %3s ",
-    pc, prefix or "  ", sub(bcnames, oidx+1, oidx+6), ma == 0 and "" or a)
+    pc, prefix or "  ", op, ma == 0 and "" or a)
   local d = shr(ins, 16)
   if mc == 13*128 then -- BCMjump
     return format("%s=> %04d\n", s, pc+d-0x7fff)
@@ -87,6 +88,7 @@ local function bcline(func, pc, prefix)
     kc = format(#kc > 40 and '"%.40s"~' or '"%s"', gsub(kc, "%c", ctlsub))
   elseif mc == 9*128 then -- BCMnum
     kc = funck(func, d)
+    if op == "TSETM " then kc = kc - 2^52 end
   elseif mc == 12*128 then -- BCMfunc
     local fi = funcinfo(funck(func, -d-1))
     if fi.ffid then
diff --git a/src/buildvm_x86.dasc b/src/buildvm_x86.dasc
index bc128457..d7c36d90 100644
--- a/src/buildvm_x86.dasc
+++ b/src/buildvm_x86.dasc
@@ -4288,15 +4288,7 @@ static void build_ins(BuildCtx *ctx, BCOp op, int defop, int cmov, int sse)
   case BC_TSETM:
     |  ins_AD	// RA = base (table at base-1), RD = num const (start index)
     |  mov TMP1, KBASE			// Need one more free register.
-    if (sse) {
-      |  cvtsd2si KBASE, qword [KBASE+RD*8]
-    } else {
-      |.if not X64
-      |  fld qword [KBASE+RD*8]
-      |  fistp ARG4			// Const is guaranteed to be an int.
-      |  mov KBASE, ARG4
-      |.endif
-    }
+    |  mov KBASE, dword [KBASE+RD*8]	// Integer constant is in lo-word.
     |1:
     |  lea RA, [BASE+RA*8]
     |  mov TAB:RB, [RA-8]		// Guaranteed to be a table.
@@ -4308,7 +4300,7 @@ static void build_ins(BuildCtx *ctx, BCOp op, int defop, int cmov, int sse)
     |  jz >4				// Nothing to copy?
     |  add RD, KBASE			// Compute needed size.
     |  cmp RD, TAB:RB->asize
-    |  jae >5				// Does not fit into array part?
+    |  jae >5				// Doesn't fit into array part?
     |  sub RD, KBASE
     |  shl KBASE, 3
     |  add KBASE, TAB:RB->array
diff --git a/src/lj_parse.c b/src/lj_parse.c
index f5f59d03..e1ca2ff7 100644
--- a/src/lj_parse.c
+++ b/src/lj_parse.c
@@ -1369,7 +1369,8 @@ static void expr_table(LexState *ls, ExpDesc *e)
     lua_assert(bc_a(ilp->ins) == freg &&
 	       bc_op(ilp->ins) == (narr > 256 ? BC_TSETV : BC_TSETB));
     expr_init(&en, VKNUM, 0);
-    setintV(&en.u.nval, narr-1);
+    en.u.nval.u32.lo = narr-1;
+    en.u.nval.u32.hi = 0x43300000;  /* Biased integer to avoid denormals. */
     if (narr > 256) { fs->pc--; ilp--; }
     ilp->ins = BCINS_AD(BC_TSETM, freg, const_num(fs, &en));
     setbc_b(&ilp[-1].ins, 0);