[PATCH 10/23] sim/erc32: Switched emulated memory to host endian order.

Jiri Gaisler
2015-02-17T07:45:39Z

Change data ordering in emulated memory from target order (big endian)
to host order. Improves performance and simplifies most memory
operations. Requires some byte twisting during stores on little
endian hosts (intel).

* erc32.c (fetch_bytes) Remove. (store_bytes) Remove byte twisting.
(memory_read) Access memory directly. (extract_short,
extract_short_signed, extract_byte, extract_byte_signed) New
function for for sub-word LD instructions.

* func.c (disp_ctrl, dis_mem) Ajust print-out to new data endian.

* interf.c (sim_open) Convert endian when gdb writes to memory.
---
sim/erc32/erc32.c | 167 ++++++++++++-----------------------------------------
sim/erc32/exec.c | 58 ++++++++++++++++---
sim/erc32/func.c | 33 +++++++----
sim/erc32/interf.c | 29 ++++++++++
sim/erc32/sis.c | 4 ++
5 files changed, 142 insertions(+), 149 deletions(-)

diff --git a/sim/erc32/erc32.c b/sim/erc32/erc32.c
index 4fa8f61..152eb1e 100644
--- a/sim/erc32/erc32.c
+++ b/sim/erc32/erc32.c
@@ -297,11 +297,8 @@ static void gpt_reload_set (uint32 val);
static void timer_ctrl (uint32 val);
static unsigned char *
get_mem_ptr (uint32 addr, uint32 size);
-
-static void fetch_bytes (int asi, unsigned char *mem,
- uint32 *data, int sz);
-
-static void store_bytes (unsigned char *mem, uint32 *data, int sz);
+static void store_bytes (unsigned char *mem, uint32 waddr,
+ uint32 *data, int sz, int32 *ws);

extern int ext_irl;

@@ -1525,123 +1522,44 @@ timer_ctrl(val)
gpt_start();
}

-
-/* Retrieve data from target memory. MEM points to location from which
- to read the data; DATA points to words where retrieved data will be
- stored in host byte order. SZ contains log(2) of the number of bytes
- to retrieve, and can be 0 (1 byte), 1 (one half-word), 2 (one word),
- or 3 (two words). */
+/* Store data in host byte order. MEM points to the beginning of the
+ emulated memory; WADDR contains the index the emulated memory,
+ DATA points to words in host byte order to be stored. SZ contains log(2)
+ of the number of bytes to retrieve, and can be 0 (1 byte), 1 (one half-word),
+ 2 (one word), or 3 (two words); WS should return the number of wait-states. */

static void
-fetch_bytes (asi, mem, data, sz)
- int asi;
+store_bytes (mem, waddr, data, sz, ws)
unsigned char *mem;
+ uint32 waddr;
uint32 *data;
- int sz;
+ int32 sz;
+ int32 *ws;
{
- if (CURRENT_TARGET_BYTE_ORDER == BIG_ENDIAN
- || asi == 8 || asi == 9) {
- switch (sz) {
- case 3:
- data[1] = (((uint32) mem[7]) & 0xff) |
- ((((uint32) mem[6]) & 0xff) << 8) |
- ((((uint32) mem[5]) & 0xff) << 16) |
- ((((uint32) mem[4]) & 0xff) << 24);
- /* Fall through to 2 */
- case 2:
- data[0] = (((uint32) mem[3]) & 0xff) |
- ((((uint32) mem[2]) & 0xff) << 8) |
- ((((uint32) mem[1]) & 0xff) << 16) |
- ((((uint32) mem[0]) & 0xff) << 24);
- break;
- case 1:
- data[0] = (((uint32) mem[1]) & 0xff) |
- ((((uint32) mem[0]) & 0xff) << 8);
- break;
+ switch (sz) {
case 0:
- data[0] = mem[0] & 0xff;
- break;
-
- }
- } else {
- switch (sz) {
- case 3:
- data[1] = ((((uint32) mem[7]) & 0xff) << 24) |
- ((((uint32) mem[6]) & 0xff) << 16) |
- ((((uint32) mem[5]) & 0xff) << 8) |
- (((uint32) mem[4]) & 0xff);
- /* Fall through to 4 */
- case 2:
- data[0] = ((((uint32) mem[3]) & 0xff) << 24) |
- ((((uint32) mem[2]) & 0xff) << 16) |
- ((((uint32) mem[1]) & 0xff) << 8) |
- (((uint32) mem[0]) & 0xff);
+#ifdef HOST_LITTLE_ENDIAN
+ waddr ^= 3;
+#endif
+ mem[waddr] = *data & 0x0ff;
+ *ws = mem_ramw_ws + 3;
break;
case 1:
- data[0] = ((((uint32) mem[1]) & 0xff) << 8) |
- (((uint32) mem[0]) & 0xff);
- break;
- case 0:
- data[0] = mem[0] & 0xff;
+#ifdef HOST_LITTLE_ENDIAN
+ waddr ^= 2;
+#endif
+ *((unsigned short *) &(mem[waddr])) = *data & 0x0ffff;
+ *ws = mem_ramw_ws + 3;
break;
- }
- }
-}
-
-
-/* Store data in target byte order. MEM points to location to store data;
- DATA points to words in host byte order to be stored. SZ contains log(2)
- of the number of bytes to retrieve, and can be 0 (1 byte), 1 (one half-word),
- 2 (one word), or 3 (two words). */
-
-static void
-store_bytes (mem, data, sz)
- unsigned char *mem;
- uint32 *data;
- int sz;
-{
- if (CURRENT_TARGET_BYTE_ORDER == LITTLE_ENDIAN) {
- switch (sz) {
- case 3:
- mem[7] = (data[1] >> 24) & 0xff;
- mem[6] = (data[1] >> 16) & 0xff;
- mem[5] = (data[1] >> 8) & 0xff;
- mem[4] = data[1] & 0xff;
- /* Fall through to 2 */
case 2:
- mem[3] = (data[0] >> 24) & 0xff;
- mem[2] = (data[0] >> 16) & 0xff;
- /* Fall through to 1 */
- case 1:
- mem[1] = (data[0] >> 8) & 0xff;
- /* Fall through to 0 */
- case 0:
- mem[0] = data[0] & 0xff;
+ *((uint32 *) &(mem[waddr])) = *data;
+ *ws = mem_ramw_ws;
break;
- }
- } else {
- switch (sz) {
case 3:
- mem[7] = data[1] & 0xff;
- mem[6] = (data[1] >> 8) & 0xff;
- mem[5] = (data[1] >> 16) & 0xff;
- mem[4] = (data[1] >> 24) & 0xff;
- /* Fall through to 2 */
- case 2:
- mem[3] = data[0] & 0xff;
- mem[2] = (data[0] >> 8) & 0xff;
- mem[1] = (data[0] >> 16) & 0xff;
- mem[0] = (data[0] >> 24) & 0xff;
- break;
- case 1:
- mem[1] = data[0] & 0xff;
- mem[0] = (data[0] >> 8) & 0xff;
- break;
- case 0:
- mem[0] = data[0] & 0xff;
+ *((uint32 *) &(mem[waddr])) = data[0];
+ *((uint32 *) &(mem[waddr + 4])) = data[1];
+ *ws = 2 * mem_ramw_ws + STD_WS;
break;
-
- }
}
}

@@ -1671,7 +1589,7 @@ memory_read(asi, addr, data, sz, ws)
#endif

if ((addr >= mem_ramstart) && (addr < (mem_ramstart + mem_ramsz))) {
- fetch_bytes (asi, &ramb[addr & mem_rammask], data, sz);
+ *data = *((uint32 *) & (ramb[addr & mem_rammask & ~3]));
*ws = mem_ramr_ws;
return (0);
} else if ((addr >= MEC_START) && (addr < MEC_END)) {
@@ -1689,7 +1607,7 @@ memory_read(asi, addr, data, sz, ws)
} else if (era) {
if ((addr < 0x100000) ||
((addr>= 0x80000000) && (addr < 0x80100000))) {
- fetch_bytes (asi, &romb[addr & ROM_MASK], data, sz);
+ *data = *((uint32 *) & (romb[addr & ROM_MASK & ~3]));
*ws = 4;
return (0);
} else if ((addr >= 0x10000000) &&
@@ -1700,13 +1618,13 @@ memory_read(asi, addr, data, sz, ws)
}

} else if (addr < mem_romsz) {
- fetch_bytes (asi, &romb[addr], data, sz);
+ *data = *((uint32 *) & (romb[addr & ~3]));
*ws = mem_romr_ws;
return (0);

#else
} else if (addr < mem_romsz) {
- fetch_bytes (asi, &romb[addr], data, sz);
+ *data = *((uint32 *) & (romb[addr & ~3]));
*ws = mem_romr_ws;
return (0);
#endif
@@ -1769,21 +1687,10 @@ memory_write(asi, addr, data, sz, ws)
}
}

- store_bytes (&ramb[addr & mem_rammask], data, sz);
-
- switch (sz) {
- case 0:
- case 1:
- *ws = mem_ramw_ws + 3;
- break;
- case 2:
- *ws = mem_ramw_ws;
- break;
- case 3:
- *ws = 2 * mem_ramw_ws + STD_WS;
- break;
- }
+ waddr = addr & mem_rammask;
+ store_bytes (ramb, waddr, data, sz, ws);
return (0);
+
} else if ((addr >= MEC_START) && (addr < MEC_END)) {
if ((sz != 2) || (asi != 0xb)) {
set_sfsr(MEC_ACC, addr, asi, 0);
@@ -1806,7 +1713,7 @@ memory_write(asi, addr, data, sz, ws)
((addr < 0x100000) || ((addr >= 0x80000000) && (addr < 0x80100000)))) {
addr &= ROM_MASK;
*ws = sz == 3 ? 8 : 4;
- store_bytes (&romb[addr], data, sz);
+ store_bytes (romb, addr, data, sz, ws);
return (0);
} else if ((addr >= 0x10000000) &&
(addr < (0x10000000 + (512 << (mec_iocr & 0x0f)))) &&
@@ -1822,7 +1729,7 @@ memory_write(asi, addr, data, sz, ws)
*ws = mem_romw_ws + 1;
if (sz == 3)
*ws += mem_romw_ws + STD_WS;
- store_bytes (&romb[addr], data, sz);
+ store_bytes (romb, addr, data, sz, ws);
return (0);

#else
@@ -1833,7 +1740,7 @@ memory_write(asi, addr, data, sz, ws)
*ws = mem_romw_ws + 1;
if (sz == 3)
*ws += mem_romw_ws + STD_WS;
- store_bytes (&romb[addr], data, sz);
+ store_bytes (romb, addr, data, sz, ws);
return (0);

#endif
diff --git a/sim/erc32/exec.c b/sim/erc32/exec.c
index 07f3586..e80e02a 100644
--- a/sim/erc32/exec.c
+++ b/sim/erc32/exec.c
@@ -371,6 +371,36 @@ div64 (uint32 n1_hi, uint32 n1_low, uint32 n2, uint32 *result, int msigned)
}

+static int
+extract_short(uint32 data, uint32 address)
+{
+ return((data>>((2 - (address & 2))*8)) & 0xffff);
+}
+
+static int
+extract_short_signed(uint32 data, uint32 address)
+{
+ uint32 tmp;
+ tmp = ((data>>((2 - (address & 2))*8)) & 0xffff);
+ if (tmp & 0x8000) tmp |= 0xffff0000;
+ return(tmp);
+}
+
+static int
+extract_byte(uint32 data, uint32 address)
+{
+ return((data>>((3 - (address & 3))*8)) & 0xff);
+}
+
+static int
+extract_byte_signed(uint32 data, uint32 address)
+{
+ uint32 tmp;
+ tmp = ((data>>((3 - (address & 3))*8)) & 0xff);
+ if (tmp & 0x80) tmp |= 0xffffff00;
+ return(tmp);
+}
+
int
dispatch_instruction(sregs)
struct pstate *sregs;
@@ -1078,7 +1108,8 @@ dispatch_instruction(sregs)
sregs->trap = TRAP_PRIVI;
break;
}
- sregs->psr = (rs1 ^ operand2) & 0x00f03fff;
+ sregs->psr = (sregs->psr & 0xff000000) |
+ (rs1 ^ operand2) & 0x00f03fff;
break;
case WRWIM:
if (!(sregs->psr & PSR_S)) {
@@ -1214,8 +1245,10 @@ dispatch_instruction(sregs)
else
rdd = &(sregs->g[rd]);
}
- mexc = memory_read(asi, address, ddata, 3, &ws);
- sregs->hold += ws * 2;
+ mexc = memory_read(asi, address, ddata, 2, &ws);
+ sregs->hold += ws;
+ mexc |= memory_read(asi, address+4, &ddata[1], 2, &ws);
+ sregs->hold += ws;
sregs->icnt = T_LDD;
if (mexc) {
sregs->trap = TRAP_DEXC;
@@ -1253,6 +1286,7 @@ dispatch_instruction(sregs)
sregs->trap = TRAP_DEXC;
break;
}
+ data = extract_byte(data, address);
*rdd = data;
data = 0x0ff;
mexc = memory_write(asi, address, &data, 0, &ws);
@@ -1275,8 +1309,10 @@ dispatch_instruction(sregs)
sregs->trap = TRAP_DEXC;
break;
}
- if ((op3 == LDSB) && (data & 0x80))
- data |= 0xffffff00;
+ if (op3 == LDSB)
+ data = extract_byte_signed(data, address);
+ else
+ data = extract_byte(data, address);
*rdd = data;
break;
case LDSHA:
@@ -1294,8 +1330,10 @@ dispatch_instruction(sregs)
sregs->trap = TRAP_DEXC;
break;
}
- if ((op3 == LDSH) && (data & 0x8000))
- data |= 0xffff0000;
+ if (op3 == LDSH)
+ data = extract_short_signed(data, address);
+ else
+ data = extract_short(data, address);
*rdd = data;
break;
case LDF:
@@ -1338,8 +1376,10 @@ dispatch_instruction(sregs)
((sregs->frs2 >> 1) == (rd >> 1)))
sregs->fhold += (sregs->ftime - ebase.simtime);
}
- mexc = memory_read(asi, address, ddata, 3, &ws);
- sregs->hold += ws * 2;
+ mexc = memory_read(asi, address, ddata, 2, &ws);
+ sregs->hold += ws;
+ mexc |= memory_read(asi, address+4, &ddata[1], 2, &ws);
+ sregs->hold += ws;
sregs->icnt = T_LDD;
if (mexc) {
sregs->trap = TRAP_DEXC;
diff --git a/sim/erc32/func.c b/sim/erc32/func.c
index a3da1c5..25ecd14 100644
--- a/sim/erc32/func.c
+++ b/sim/erc32/func.c
@@ -777,15 +777,15 @@ disp_ctrl(sregs)
struct pstate *sregs;
{

- unsigned char i[4];
+ uint32 i;

printf("\n psr: %08X wim: %08X tbr: %08X y: %08X\n",
sregs->psr, sregs->wim, sregs->tbr, sregs->y);
- sis_memory_read(sregs->pc, i, 4);
- printf("\n pc: %08X = %02X%02X%02X%02X ", sregs->pc,i[0],i[1],i[2],i[3]);
+ sis_memory_read(sregs->pc, (char *) &i, 4);
+ printf("\n pc: %08X = %08X ", sregs->pc, i);
print_insn_sparc_sis(sregs->pc, &dinfo);
- sis_memory_read(sregs->npc, i, 4);
- printf("\n npc: %08X = %02X%02X%02X%02X ",sregs->npc,i[0],i[1],i[2],i[3]);
+ sis_memory_read(sregs->npc, (char *) &i, 4);
+ printf("\n npc: %08X = %08X ", sregs->npc, i);
print_insn_sparc_sis(sregs->npc, &dinfo);
if (sregs->err_mode)
printf("\n IU in error mode");
@@ -800,21 +800,28 @@ disp_mem(addr, len)

uint32 i;
unsigned char data[4];
+ uint32 *wdata = (uint32 *) data;
uint32 mem[4], j;
char *p;
+ int end;

+#ifdef HOST_LITTLE_ENDIAN
+ end = 3;
+#else
+ end = 0;
+#endif
for (i = addr & ~3; i < ((addr + len) & ~3); i += 16) {
printf("\n %8X ", i);
for (j = 0; j < 4; j++) {
sis_memory_read((i + (j * 4)), data, 4);
- printf("%02x%02x%02x%02x ", data[0],data[1],data[2],data[3]);
+ printf("%08x ", *wdata);
mem[j] = *((int *) &data);
}
printf(" ");
p = (char *) mem;
for (j = 0; j < 16; j++) {
- if (isprint(p[j]))
- putchar(p[j]);
+ if (isprint(p[j^end]))
+ putchar(p[j^end]);
else
putchar('.');
}
@@ -830,10 +837,11 @@ dis_mem(addr, len, info)
{
uint32 i;
unsigned char data[4];
+ uint32 *wdata = (uint32 *) data;

for (i = addr & -3; i < ((addr & -3) + (len << 2)); i += 4) {
sis_memory_read(i, data, 4);
- printf(" %08x %02x%02x%02x%02x ", i, data[0],data[1],data[2],data[3]);
+ printf(" %08x %08x ", i, *wdata);
print_insn_sparc_sis(i, info);
if (i >= 0xfffffffc) break;
printf("\n");
@@ -1032,6 +1040,7 @@ bfd_load(fname)
asection *section;
bfd *pbfd;
const bfd_arch_info_type *arch;
+ int i;

pbfd = bfd_openr(fname, 0);

@@ -1105,13 +1114,17 @@ bfd_load(fname)
fptr = 0;

while (section_size > 0) {
- char buffer[1024];
int count;
+ char buffer[1024];
+ uint32 *wbuffer = (uint32 *) buffer;

count = min(section_size, 1024);

bfd_get_section_contents(pbfd, section, buffer, fptr, count);

+#ifdef HOST_LITTLE_ENDIAN
+ for (i=0;i<count/4;i++) wbuffer[i] = ntohl(wbuffer[i]); // endian swap
+#endif
sis_memory_write(section_address, buffer, count);

section_address += count;
diff --git a/sim/erc32/interf.c b/sim/erc32/interf.c
index 38a2a0d..3a72e7f 100644
--- a/sim/erc32/interf.c
+++ b/sim/erc32/interf.c
@@ -265,7 +265,11 @@ sim_open (kind, callback, abfd, argv)
sregs.freq = freq ? freq : 15;
termsave = fcntl(0, F_GETFL, 0);
INIT_DISASSEMBLE_INFO(dinfo, stdout,(fprintf_ftype)fprintf);
+#ifdef HOST_LITTLE_ENDIAN
+ dinfo.endian = BFD_ENDIAN_LITTLE;
+#else
dinfo.endian = BFD_ENDIAN_BIG;
+#endif
reset_all();
ebase.simtime = 0;
init_sim();
@@ -355,7 +359,19 @@ sim_write(sd, mem, buf, length)
const unsigned char *buf;
int length;
{
+#ifdef HOST_LITTLE_ENDIAN
+ int *ibufp = (int *) buf;
+ int ibuf[8192];
+ int i, len;
+
+ if (length >= 4)
+ for (i=0; i<length; i+=4) {
+ ibuf[i] = ntohl(ibufp[i]);
+ }
+ return (sis_memory_write(mem, (char *) ibuf, length));
+#else
return (sis_memory_write(mem, buf, length));
+#endif
}

int
@@ -365,7 +381,20 @@ sim_read(sd, mem, buf, length)
unsigned char *buf;
int length;
{
+#ifdef HOST_LITTLE_ENDIAN
+ int *ibuf = (int *) buf;
+ int i, len;
+
+ len = sis_memory_read(mem, buf, length);
+ if (length >= 4)
+ for (i=0; i<length; i+=4) {
+ *ibuf = htonl(*ibuf);
+ ibuf++;
+ }
+ return (len);
+#else
return (sis_memory_read(mem, buf, length));
+#endif
}

void
diff --git a/sim/erc32/sis.c b/sim/erc32/sis.c
index 97f1b31..c6e9714 100644
--- a/sim/erc32/sis.c
+++ b/sim/erc32/sis.c
@@ -237,7 +237,11 @@ main(argc, argv)
sregs.freq = freq;

INIT_DISASSEMBLE_INFO(dinfo, stdout, (fprintf_ftype) fprintf);
+#ifdef HOST_LITTLE_ENDIAN
+ dinfo.endian = BFD_ENDIAN_LITTLE;
+#else
dinfo.endian = BFD_ENDIAN_BIG;
+#endif

termsave = fcntl(0, F_GETFL, 0);
using_history();
--
2.1.0