From 9e99ccc360bc9784ebe5ce29d5fa2c72acfc5777 Mon Sep 17 00:00:00 2001
From: Mike Pall <mike>
Date: Mon, 23 May 2016 00:27:51 +0200
Subject: [PATCH] Strip out old infrastructure for 64 bit constants.

Contributed by Peter Cawley.
---
 src/lj_ir.c    | 74 --------------------------------------------------
 src/lj_iropt.h |  3 --
 src/lj_jit.h   |  1 -
 src/lj_trace.c |  2 --
 4 files changed, 80 deletions(-)

diff --git a/src/lj_ir.c b/src/lj_ir.c
index 124d5791..9c0a2224 100644
--- a/src/lj_ir.c
+++ b/src/lj_ir.c
@@ -204,80 +204,6 @@ found:
   return TREF(ref, IRT_INT);
 }
 
-/* The MRef inside the KNUM/KINT64 IR instructions holds the address of the
-** 64 bit constant. The constants themselves are stored in a chained array
-** and shared across traces.
-**
-** Rationale for choosing this data structure:
-** - The address of the constants is embedded in the generated machine code
-**   and must never move. A resizable array or hash table wouldn't work.
-** - Most apps need very few non-32 bit integer constants (less than a dozen).
-** - Linear search is hard to beat in terms of speed and low complexity.
-*/
-typedef struct K64Array {
-  MRef next;			/* Pointer to next list. */
-  MSize numk;			/* Number of used elements in this array. */
-  TValue k[LJ_MIN_K64SZ];	/* Array of constants. */
-} K64Array;
-
-/* Free all chained arrays. */
-void lj_ir_k64_freeall(jit_State *J)
-{
-  K64Array *k;
-  for (k = mref(J->k64p, K64Array); k; ) {
-    K64Array *next = mref(k->next, K64Array);
-    lj_mem_free(J2G(J), k, sizeof(K64Array));
-    k = next;
-  }
-  setmref(J->k64p, NULL);
-}
-
-/* Get new 64 bit constant slot. */
-static TValue *ir_k64_add(jit_State *J, K64Array *kp, uint64_t u64)
-{
-  TValue *ntv;
-  if (!(kp && kp->numk < LJ_MIN_K64SZ)) {  /* Allocate a new array. */
-    K64Array *kn = lj_mem_newt(J->L, sizeof(K64Array), K64Array);
-    setmref(kn->next, NULL);
-    kn->numk = 0;
-    if (kp)
-      setmref(kp->next, kn);  /* Chain to the end of the list. */
-    else
-      setmref(J->k64p, kn);  /* Link first array. */
-    kp = kn;
-  }
-  ntv = &kp->k[kp->numk++];  /* Add to current array. */
-  ntv->u64 = u64;
-  return ntv;
-}
-
-/* Find 64 bit constant in chained array or add it. */
-cTValue *lj_ir_k64_find(jit_State *J, uint64_t u64)
-{
-  K64Array *k, *kp = NULL;
-  MSize idx;
-  /* Search for the constant in the whole chain of arrays. */
-  for (k = mref(J->k64p, K64Array); k; k = mref(k->next, K64Array)) {
-    kp = k;  /* Remember previous element in list. */
-    for (idx = 0; idx < k->numk; idx++) {  /* Search one array. */
-      TValue *tv = &k->k[idx];
-      if (tv->u64 == u64)  /* Needed for +-0/NaN/absmask. */
-	return tv;
-    }
-  }
-  /* Otherwise add a new constant. */
-  return ir_k64_add(J, kp, u64);
-}
-
-TValue *lj_ir_k64_reserve(jit_State *J)
-{
-  K64Array *k, *kp = NULL;
-  lj_ir_k64_find(J, 0);  /* Intern dummy 0 to protect the reserved slot. */
-  /* Find last K64Array, if any. */
-  for (k = mref(J->k64p, K64Array); k; k = mref(k->next, K64Array)) kp = k;
-  return ir_k64_add(J, kp, 0);  /* Set to 0. Final value is set later. */
-}
-
 /* Intern 64 bit constant, given by its 64 bit pattern. */
 TRef lj_ir_k64(jit_State *J, IROp op, uint64_t u64)
 {
diff --git a/src/lj_iropt.h b/src/lj_iropt.h
index 219d391a..8b7a43de 100644
--- a/src/lj_iropt.h
+++ b/src/lj_iropt.h
@@ -40,10 +40,7 @@ LJ_FUNC TRef lj_ir_ggfload(jit_State *J, IRType t, uintptr_t ofs);
 
 /* Interning of constants. */
 LJ_FUNC TRef LJ_FASTCALL lj_ir_kint(jit_State *J, int32_t k);
-LJ_FUNC void lj_ir_k64_freeall(jit_State *J);
 LJ_FUNC TRef lj_ir_k64(jit_State *J, IROp op, uint64_t u64);
-LJ_FUNC TValue *lj_ir_k64_reserve(jit_State *J);
-LJ_FUNC cTValue *lj_ir_k64_find(jit_State *J, uint64_t u64);
 LJ_FUNC TRef lj_ir_knum_u64(jit_State *J, uint64_t u64);
 LJ_FUNC TRef lj_ir_knumint(jit_State *J, lua_Number n);
 LJ_FUNC TRef lj_ir_kint64(jit_State *J, uint64_t u64);
diff --git a/src/lj_jit.h b/src/lj_jit.h
index e9ab319e..55fbea8b 100644
--- a/src/lj_jit.h
+++ b/src/lj_jit.h
@@ -392,7 +392,6 @@ typedef struct jit_State {
   int32_t framedepth;	/* Current frame depth. */
   int32_t retdepth;	/* Return frame depth (count of RETF). */
 
-  MRef k64p;		/* Pointer to chained array of 64 bit constants. */
   TValue ksimd[LJ_KSIMD__MAX*2+1];  /* 16 byte aligned SIMD constants. */
   TValue k64[LJ_K64__MAX];  /* Common 8 byte constants used by backends. */
   uint32_t k32[LJ_K32__MAX];  /* Ditto for 4 byte constants. */
diff --git a/src/lj_trace.c b/src/lj_trace.c
index eaf9365c..87146832 100644
--- a/src/lj_trace.c
+++ b/src/lj_trace.c
@@ -295,7 +295,6 @@ int lj_trace_flushall(lua_State *L)
   memset(J->penalty, 0, sizeof(J->penalty));
   /* Free the whole machine code and invalidate all exit stub groups. */
   lj_mcode_free(J);
-  lj_ir_k64_freeall(J);
   memset(J->exitstubgroup, 0, sizeof(J->exitstubgroup));
   lj_vmevent_send(L, TRACE,
     setstrV(L, L->top++, lj_str_newlit(L, "flush"));
@@ -351,7 +350,6 @@ void lj_trace_freestate(global_State *g)
   }
 #endif
   lj_mcode_free(J);
-  lj_ir_k64_freeall(J);
   lj_mem_freevec(g, J->snapmapbuf, J->sizesnapmap, SnapEntry);
   lj_mem_freevec(g, J->snapbuf, J->sizesnap, SnapShot);
   lj_mem_freevec(g, J->irbuf + J->irbotlim, J->irtoplim - J->irbotlim, IRIns);