diff --git a/ChangeLog b/ChangeLog
index 898caa9de..479d99e72 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2012-12-20 Paulo Andrade <pcpa@gnu.org>
+
+	* include/lightning/jit_ppc.h: Correct mismatch of JIT_F{1,5}
+	with enum codes, that were correct, and returned by jit_f().
+
+	* lib/jit_ppc-cpu.c, lib/jit_ppc-fpu.c, lib/jit_ppc.c: Properly
+	implement and better describe values when generating stack
+	frames.
+
 2012-12-18 Paulo Andrade <pcpa@gnu.org>
 
 	* check/stack.ok, check/stack.tst: New files to test data
diff --git a/include/lightning/jit_ppc.h b/include/lightning/jit_ppc.h
index d42b8cc55..ee076480f 100644
--- a/include/lightning/jit_ppc.h
+++ b/include/lightning/jit_ppc.h
@@ -74,11 +74,11 @@ typedef enum {
 #define JIT_RA7			_R10
     _R10,	_R9,	_R8,	_R7,	_R6,	_R5,	_R4,	_R3,
 #  define JIT_F0		_F0
-#  define JIT_F1		_F8
-#  define JIT_F2		_F9
-#  define JIT_F3		_F10
-#  define JIT_F4		_F11
-#  define JIT_F5		_F12
+#  define JIT_F1		_F9
+#  define JIT_F2		_F10
+#  define JIT_F3		_F11
+#  define JIT_F4		_F12
+#  define JIT_F5		_F13
     _F0,	_F9,	_F10,	_F11,	_F12,	_F13,
 #define JIT_FS0			_F14
 #define JIT_FS1			_F15
diff --git a/lib/jit_ppc-cpu.c b/lib/jit_ppc-cpu.c
index 0f9b34348..868fcc1fa 100644
--- a/lib/jit_ppc-cpu.c
+++ b/lib/jit_ppc-cpu.c
@@ -16,7 +16,11 @@
  */
 
 #if PROTO
-#  define stack_framesize		80
+#  define gpr_save_area			72	/* r14~r31 = 18 * 4 */
+#  define fpr_save_area			0	/* FIXME extra fpr registers
+						 * not used */
+#  define alloca_offset			-(gpr_save_area + fpr_save_area)
+#  define params_offset			56
 #  define ii(i)				*_jit->pc.ui++ = i
 #  define can_sign_extend_short_p(im)	((im) >= -32768 && (im) <= 32767)
 #  define can_zero_extend_short_p(im)	((im) >= 0 && (im) <= 65535)
@@ -2363,7 +2367,7 @@ _prolog(jit_state_t *_jit, jit_node_t *node)
 {
     unsigned long	regno;
 
-    _jit->function->stack = ((_jit->function->self.alen -
+    _jit->function->stack = ((_jit->function->self.alen + params_offset -
 			      _jit->function->self.aoff) + 15) & -16;
 
     /* return address */
@@ -2376,8 +2380,12 @@ _prolog(jit_state_t *_jit, jit_node_t *node)
     STMW(rn(regno), _SP_REGNO, -(32 * 4) + rn(regno) * 4);
 
     stxi(8, _SP_REGNO, _R0_REGNO);
-    STWU(_SP_REGNO, _SP_REGNO, -(stack_framesize + _jit->function->stack + 16));
-    addi(_FP_REGNO, _SP_REGNO, _jit->function->stack + 16);
+
+    /* params >= %r31+56
+     * alloca <  %r31-80 */
+    movr(_FP_REGNO, _SP_REGNO);
+
+    STWU(_SP_REGNO, _SP_REGNO, -_jit->function->stack);
 }
 
 static void
@@ -2385,7 +2393,6 @@ _epilog(jit_state_t *_jit, jit_node_t *node)
 {
     unsigned long	regno;
 
-    //ldxi(_SP_REGNO, _SP_REGNO, 0);
     LWZ(_SP_REGNO, _SP_REGNO, 0);
     ldxi(_R0_REGNO, _SP_REGNO, 8);
 
diff --git a/lib/jit_ppc-fpu.c b/lib/jit_ppc-fpu.c
index d22d5870b..bb4964180 100644
--- a/lib/jit_ppc-fpu.c
+++ b/lib/jit_ppc-fpu.c
@@ -440,10 +440,10 @@ _extr_d(jit_state_t *_jit, jit_int32_t r0, jit_int32_t r1)
     reg = jit_get_reg(jit_class_gpr);
     rshi(rn(reg), r1, 31);
     /* use reserved 8 bytes area */
-    stxi(-4, _FP_REGNO, r1);
-    stxi(-8, _FP_REGNO, rn(reg));
+    stxi(alloca_offset - 4, _FP_REGNO, r1);
+    stxi(alloca_offset - 8, _FP_REGNO, rn(reg));
     jit_unget_reg(reg);
-    ldxi_d(r0, _FP_REGNO, -8);
+    ldxi_d(r0, _FP_REGNO, alloca_offset - 8);
     FCFID(r0, r0);
 }
 
@@ -454,8 +454,8 @@ _truncr_d(jit_state_t *_jit, jit_int32_t r0, jit_int32_t r1)
     reg = jit_get_reg(jit_class_fpr);
     FCTIWZ(rn(reg), r1);
     /* use reserved 8 bytes area */
-    stxi_d(-8, _FP_REGNO, rn(reg));
-    ldxi(r0, _FP_REGNO, -4);
+    stxi_d(alloca_offset - 8, _FP_REGNO, rn(reg));
+    ldxi(r0, _FP_REGNO, alloca_offset - 4);
     jit_unget_reg(reg);
 }
 
diff --git a/lib/jit_ppc.c b/lib/jit_ppc.c
index 9fdc10d29..ddb6ad019 100644
--- a/lib/jit_ppc.c
+++ b/lib/jit_ppc.c
@@ -136,11 +136,11 @@ _jit_prolog(jit_state_t *_jit)
 	_jit->functions.length += 16;
     }
     _jit->function = _jit->functions.ptr + _jit->functions.offset++;
-    _jit->function->self.size = stack_framesize;
+    _jit->function->self.size = params_offset;
     _jit->function->self.argi = _jit->function->self.argf =
-	_jit->function->self.aoff = _jit->function->self.alen = 0;
+	_jit->function->self.alen = 0;
     /* float conversion */
-    _jit->function->self.aoff = -8;
+    _jit->function->self.aoff = alloca_offset - 8;
     _jit->function->self.call = jit_call_default;
     _jit->function->regoff = calloc(_jit->reglen, sizeof(jit_int32_t));
 
@@ -372,9 +372,7 @@ _jit_pushargr(jit_state_t *_jit, jit_int32_t u)
 	++_jit->function->call.argi;
     }
     else {
-	if (!_jit->function->call.size)
-	    _jit->function->call.size = 56;
-	jit_stxi(_jit->function->call.size, JIT_SP, u);
+	jit_stxi(_jit->function->call.size + params_offset, JIT_SP, u);
 	_jit->function->call.size += sizeof(jit_word_t);
     }
 }
@@ -389,11 +387,9 @@ _jit_pushargi(jit_state_t *_jit, jit_word_t u)
 	++_jit->function->call.argi;
     }
     else {
-	if (!_jit->function->call.size)
-	    _jit->function->call.size = 56;
 	regno = jit_get_reg(jit_class_gpr);
 	jit_movi(regno, u);
-	jit_stxi(_jit->function->call.size, JIT_SP, regno);
+	jit_stxi(_jit->function->call.size + params_offset, JIT_SP, regno);
 	_jit->function->call.size += sizeof(jit_word_t);
 	jit_unget_reg(regno);
     }
@@ -418,20 +414,24 @@ _jit_pushargr_d(jit_state_t *_jit, jit_int32_t u)
     if (_jit->function->call.argf < 8) {
 	jit_movr_d(JIT_FA0 - _jit->function->call.argf, u);
 	++_jit->function->call.argf;
-	if (!(_jit->function->call.call & jit_call_varargs))
+	if (!(_jit->function->call.call & jit_call_varargs)) {
+	    /* in case of excess arguments */
+	    ++_jit->function->call.argi;
 	    return;
+	}
     }
     if (_jit->function->call.argi < 8) {
-	jit_stxi_d(-8, JIT_FP, u);
-	jit_ldxi(JIT_RA0 - _jit->function->call.argi, JIT_FP, -8);
+	/* use reserved 8 bytes area */
+	jit_stxi_d(alloca_offset - 8, JIT_FP, u);
+	jit_ldxi(JIT_RA0 - _jit->function->call.argi, JIT_FP,
+		 alloca_offset - 8);
 	_jit->function->call.argi++;
-	jit_ldxi(JIT_RA0 - _jit->function->call.argi, JIT_FP, -4);
+	jit_ldxi(JIT_RA0 - _jit->function->call.argi, JIT_FP,
+		 alloca_offset - 4);
 	_jit->function->call.argi++;
     }
     else {
-	if (!_jit->function->call.size)
-	    _jit->function->call.size = 56;
-	jit_stxi_d(_jit->function->call.size, JIT_SP, u);
+	jit_stxi_d(_jit->function->call.size + params_offset, JIT_SP, u);
 	_jit->function->call.size += sizeof(jit_float64_t);
     }
 }
@@ -445,22 +445,26 @@ _jit_pushargi_d(jit_state_t *_jit, jit_float64_t u)
     if (_jit->function->call.argf < 8) {
 	jit_movi_d(JIT_FA0 - _jit->function->call.argf, u);
 	++_jit->function->call.argf;
-	if (!(_jit->function->call.call & jit_call_varargs))
+	if (!(_jit->function->call.call & jit_call_varargs)) {
+	    /* in case of excess arguments */
+	    ++_jit->function->call.argi;
 	    return;
+	}
     }
     regno = jit_get_reg(jit_class_fpr);
     jit_movi_d(regno, u);
     if (_jit->function->call.argi < 8) {
-	jit_stxi_d(-8, JIT_FP, regno);
-	jit_ldxi(JIT_RA0 - _jit->function->call.argi, JIT_FP, -8);
+	/* use reserved 8 bytes area */
+	jit_stxi_d(alloca_offset - 8, JIT_FP, regno);
+	jit_ldxi(JIT_RA0 - _jit->function->call.argi, JIT_FP,
+		 alloca_offset - 8);
 	_jit->function->call.argi++;
-	jit_ldxi(JIT_RA0 - _jit->function->call.argi, JIT_FP, -4);
+	jit_ldxi(JIT_RA0 - _jit->function->call.argi, JIT_FP,
+		 alloca_offset - 4);
 	_jit->function->call.argi++;
     }
     else {
-	if (!_jit->function->call.size)
-	    _jit->function->call.size = 56;
-	jit_stxi_d(_jit->function->call.size, JIT_SP, regno);
+	jit_stxi_d(_jit->function->call.size + params_offset, JIT_SP, regno);
 	_jit->function->call.size += sizeof(jit_float64_t);
     }
     jit_unget_reg(regno);
@@ -496,8 +500,7 @@ _jit_finishr(jit_state_t *_jit, jit_int32_t r0)
     call = jit_callr(r0);
     call->v.w = _jit->function->call.argi;
     call->w.w = _jit->function->call.argf;
-    _jit->function->call.argi = _jit->function->call.argf =
-	_jit->function->call.size = 0;
+    _jit->function->call.argi = _jit->function->call.argf = 0;
     _jit->prepare = 0;
 }
 
@@ -511,8 +514,7 @@ _jit_finishi(jit_state_t *_jit, jit_pointer_t i0)
     node = jit_calli(i0);
     node->v.w = _jit->function->call.argi;
     node->w.w = _jit->function->call.argf;
-    _jit->function->call.argi = _jit->function->call.argf =
-	_jit->function->call.size = 0;
+    _jit->function->call.argi = _jit->function->call.argf = 0;
     _jit->prepare = 0;
     return (node);
 }