From 25b4e1181413daed80203c79a6f574b1c7f538a9 Mon Sep 17 00:00:00 2001
From: Jin Guojie <jinguojie@loongson.cn>
Date: Thu, 1 Mar 2018 12:53:38 -0500
Subject: [PATCH] tcg-mips: Adjust calling conventions for mips64

Backports commit 999b941633cabf2487d9bc77ce382b3fde3cd66d from qemu
---
 qemu/tcg/mips/tcg-target.h     | 19 +++++++++++++++----
 qemu/tcg/mips/tcg-target.inc.c | 21 +++++++++++++++------
 2 files changed, 30 insertions(+), 10 deletions(-)

diff --git a/qemu/tcg/mips/tcg-target.h b/qemu/tcg/mips/tcg-target.h
index 4b7d3ae8..d352c973 100644
--- a/qemu/tcg/mips/tcg-target.h
+++ b/qemu/tcg/mips/tcg-target.h
@@ -27,7 +27,14 @@
 #ifndef MIPS_TCG_TARGET_H
 #define MIPS_TCG_TARGET_H
 
-#define TCG_TARGET_REG_BITS 32
+#if _MIPS_SIM == _ABIO32
+# define TCG_TARGET_REG_BITS 32
+#elif _MIPS_SIM == _ABIN32 || _MIPS_SIM == _ABI64
+# define TCG_TARGET_REG_BITS 64
+#else
+# error "Unknown ABI"
+#endif
+
 #define TCG_TARGET_INSN_UNIT_SIZE 4
 #define TCG_TARGET_TLB_DISPLACEMENT_BITS 16
 #define TCG_TARGET_NB_REGS 32
@@ -71,9 +78,13 @@ typedef enum {
 } TCGReg;
 
 /* used for function call generation */
-#define TCG_TARGET_STACK_ALIGN 8
-#define TCG_TARGET_CALL_STACK_OFFSET 16
-#define TCG_TARGET_CALL_ALIGN_ARGS 1
+#define TCG_TARGET_STACK_ALIGN        16
+#if _MIPS_SIM == _ABIO32
+# define TCG_TARGET_CALL_STACK_OFFSET 16
+#else
+# define TCG_TARGET_CALL_STACK_OFFSET 0
+#endif
+#define TCG_TARGET_CALL_ALIGN_ARGS    1
 
 /* MOVN/MOVZ instructions detection */
 #if (defined(__mips_isa_rev) && (__mips_isa_rev >= 1)) || \
diff --git a/qemu/tcg/mips/tcg-target.inc.c b/qemu/tcg/mips/tcg-target.inc.c
index 15a017cc..60497945 100644
--- a/qemu/tcg/mips/tcg-target.inc.c
+++ b/qemu/tcg/mips/tcg-target.inc.c
@@ -91,10 +91,6 @@ static const int tcg_target_reg_alloc_order[] = {
     TCG_REG_S8,
 
     /* Call clobbered registers.  */
-    TCG_REG_T0,
-    TCG_REG_T1,
-    TCG_REG_T2,
-    TCG_REG_T3,
     TCG_REG_T4,
     TCG_REG_T5,
     TCG_REG_T6,
@@ -105,17 +101,27 @@ static const int tcg_target_reg_alloc_order[] = {
     TCG_REG_V0,
 
     /* Argument registers, opposite order of allocation.  */
+    TCG_REG_T3,
+    TCG_REG_T2,
+    TCG_REG_T1,
+    TCG_REG_T0,
     TCG_REG_A3,
     TCG_REG_A2,
     TCG_REG_A1,
     TCG_REG_A0,
 };
 
-static const TCGReg tcg_target_call_iarg_regs[4] = {
+static const TCGReg tcg_target_call_iarg_regs[] = {
     TCG_REG_A0,
     TCG_REG_A1,
     TCG_REG_A2,
-    TCG_REG_A3
+    TCG_REG_A3,
+#if _MIPS_SIM == _ABIN32 || _MIPS_SIM == _ABI64
+    TCG_REG_T0,
+    TCG_REG_T1,
+    TCG_REG_T2,
+    TCG_REG_T3,
+#endif
 };
 
 static const TCGReg tcg_target_call_oarg_regs[2] = {
@@ -2443,6 +2449,9 @@ static void tcg_target_init(TCGContext *s)
 {
     tcg_target_detect_isa();
     tcg_regset_set(s->tcg_target_available_regs[TCG_TYPE_I32], 0xffffffff);
+    if (TCG_TARGET_REG_BITS == 64) {
+        tcg_regset_set(s->tcg_target_available_regs[TCG_TYPE_I64], 0xffffffff);
+    }
     tcg_regset_set(s->tcg_target_call_clobber_regs,
                    (1 << TCG_REG_V0) |
                    (1 << TCG_REG_V1) |