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Major bugfix where instructions weren't being shrunk correctly. (Turns out there's built-in support for doing this, which I hadn't found.)

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--HG--
branch : dtrg-videocore
This commit is contained in:
David Given 2013-05-25 23:26:10 +01:00
parent b6680a48cc
commit 3b07fee160
2 changed files with 88 additions and 133 deletions
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2
mach/vc4/as/mach1.c
View file

@ -10,7 +10,7 @@
#define ALWAYS 14 #define ALWAYS 14
extern void alu_instr_reg(quad opcode, int cc, int rd, int ra, int rb); extern void alu_instr_reg(quad opcode, int cc, int rd, int ra, int rb);
extern void alu_instr_lit(quad opcode, int cc, int rd, int ra, quad value); extern void alu_instr_lit(quad opcode, int cc, int rd, int ra, long value);
extern void misc_instr_reg(quad opcode, int cc, int rd, int ra, int rb); extern void misc_instr_reg(quad opcode, int cc, int rd, int ra, int rb);
extern void misc_instr_lit(quad opcode, int cc, int rd, int ra, quad value); extern void misc_instr_lit(quad opcode, int cc, int rd, int ra, quad value);
extern void branch_instr(int bl, int cc, struct expr_t* expr); extern void branch_instr(int bl, int cc, struct expr_t* expr);

219
mach/vc4/as/mach5.c
View file

@ -34,12 +34,12 @@ void alu_instr_reg(quad op, int cc, int rd, int ra, int rb)
/* Assemble an ALU instruction where rb is a literal. */ /* Assemble an ALU instruction where rb is a literal. */
void alu_instr_lit(quad op, int cc, int rd, int ra, quad value) void alu_instr_lit(quad op, int cc, int rd, int ra, long value)
{ {
/* 16 bit short form? */ /* 16 bit short form? */
if ((cc == ALWAYS) && !(op & 1) && (value <= 0x1f) && (ra == rd) && if ((cc == ALWAYS) && !(op & 1) && (value >= 0) && (value <= 0x1f) &&
(ra < 0x10)) (ra == rd) && (ra < 0x10))
{ {
emit2(B16(01100000,00000000) | (op<<8) | (value<<4) | (rd<<0)); emit2(B16(01100000,00000000) | (op<<8) | (value<<4) | (rd<<0));
return; return;
@ -47,7 +47,7 @@ void alu_instr_lit(quad op, int cc, int rd, int ra, quad value)
/* 32 bit medium form? */ /* 32 bit medium form? */
if (value <= 0x1f) if ((value >= 0) && (value <= 0x1f))
{ {
emit2(B16(11000000,00000000) | (op<<5) | (rd<<0)); emit2(B16(11000000,00000000) | (op<<5) | (rd<<0));
emit2(B16(00000000,01000000) | (ra<<11) | (cc<<7) | (value<<0)); emit2(B16(00000000,01000000) | (ra<<11) | (cc<<7) | (value<<0));
@ -99,6 +99,7 @@ void branch_instr(int bl, int cc, struct expr_t* expr)
{ {
quad pc = DOTVAL; quad pc = DOTVAL;
quad type = expr->typ & S_TYP; quad type = expr->typ & S_TYP;
int d;
/* Sanity checking. */ /* Sanity checking. */
@ -107,71 +108,52 @@ void branch_instr(int bl, int cc, struct expr_t* expr)
if (type == S_ABS) if (type == S_ABS)
serror("can't use absolute addresses here"); serror("can't use absolute addresses here");
switch (pass) /* The VC4 branch instructions express distance in 2-byte
* words. */
d = (int32_t)expr->val - (int32_t)pc;
if ((pass == 2) && (d > 0) && !(expr->typ & S_DOT))
d -= DOTGAIN;
d /= 2;
/* If this is a reference to code within this section, and it's
* close enough to the program counter, we can use a short-
* form instruction. */
if (small(!bl && (type == DOTTYP) && fitx(d, 7), 2))
{
emit2(B16(00011000,00000000) | (cc<<7) | (d&0x7f));
return;
}
/* Absolute addresses and references to other sections
* need the full 32 bits. */
newrelo(expr->typ, RELOVC4|RELPC);
if (bl)
{ {
case 0: quad v, hiv, lov;
/* Calculate size of instructions only. For now we just assume
* that they're going to be the maximum size, 32 bits. */
emit4(0); if (!fitx(d, 27))
break; toobig();
case 1: v = maskx(d, 27);
case 2: hiv = v >> 23;
{ lov = v & 0x007fffff;
/* The VC4 branch instructions express distance in 2-byte emit2(B16(10010000,10000000) | (lov>>16) | (hiv<<8));
* words. */ emit2(B16(00000000,00000000) | (lov&0xffff));
}
else
{
quad v;
int d = ((int32_t)expr->val - (int32_t)pc) / 2; if (!fitx(d, 23))
toobig();
/* We now know the worst case for the instruction layout. At v = maskx(d, 23);
* this point we can emit the instructions, which may shrink emit2(B16(10010000,00000000) | (cc<<8) | (v>>16));
* the code. */ emit2(B16(00000000,00000000) | (v&0xffff));
if (!bl && (type == DOTTYP))
{
/* This is a reference to code within this section. If it's
* close enough to the program counter, we can use a short-
* form instruction. */
if (fitx(d, 7))
{
emit2(B16(00011000,00000000) | (cc<<7) | (d&0x7f));
break;
}
}
/* Absolute addresses and references to other sections
* need the full 32 bits. */
newrelo(expr->typ, RELOVC4|RELPC);
if (bl)
{
quad v, hiv, lov;
if (!fitx(d, 27))
toobig();
v = maskx(d, 27);
hiv = v >> 23;
lov = v & 0x007fffff;
emit2(B16(10010000,10000000) | (lov>>16) | (hiv<<8));
emit2(B16(00000000,00000000) | (lov&0xffff));
}
else
{
quad v;
if (!fitx(d, 23))
toobig();
v = maskx(d, 23);
emit2(B16(10010000,00000000) | (cc<<8) | (v>>16));
emit2(B16(00000000,00000000) | (v&0xffff));
}
break;
}
} }
} }
@ -352,66 +334,45 @@ void mem_postincr_instr(quad opcode, int cc, int rd, int rs)
void mem_address_instr(quad opcode, int rd, struct expr_t* expr) void mem_address_instr(quad opcode, int rd, struct expr_t* expr)
{ {
static const char sizes[] = {4, 2, 1, 2}; static const char sizes[] = {4, 4, 2, 2, 1, 1, 2, 2};
int size = sizes[opcode]; int size = sizes[opcode];
quad type = expr->typ & S_TYP; quad type = expr->typ & S_TYP;
int d, scaledd;
/* Sanity checking. */ /* Sanity checking. */
if (type == S_ABS) if (type == S_ABS)
serror("can't use absolute addresses here"); serror("can't use absolute addresses here");
switch (pass) d = expr->val - DOTVAL;
if ((pass == 2) && (d > 0) && !(expr->typ & S_DOT))
d -= DOTGAIN;
scaledd = d/size;
/* If this is a reference to an address within this section, and
* it's close enough to the program counter, we can use a
* shorter instruction. */
if (small((type==DOTTYP) && fitx(scaledd, 16), 2))
{ {
case 0: emit2(B16(10101010,00000000) | (opcode<<5) | (rd<<0));
/* Calculate size of instructions only. For now we just assume emit2(scaledd);
* that they're going to be the maximum size, 48 bits. */ return;
}
emit2(0); /* Otherwise we need the full 48 bits. */
emit4(0);
break;
case 1: newrelo(expr->typ, RELOVC4|RELPC);
case 2:
{
int d = expr->val - DOTVAL;
/* We now know the worst case for the instruction layout. At /* VC4 relocations store the PC-relative delta into the
* this point we can emit the instructions, which may shrink * destination section in the instruction data. The linker will
* the code. */ * massage this, and scale it appropriately. */
if (type == DOTTYP) if (!fitx(d, 27))
{ toobig();
int scaledd = d/size;
/* This is a reference to an address within this section. If emit2(B16(11100111,00000000) | (opcode<<5) | (rd<<0));
* it's close enough to the program counter, we can use a emit4((31<<27) | maskx(d, 27));
* shorter instruction. */
if (fitx(scaledd, 16))
{
emit2(B16(10101010,00000000) | (opcode<<5) | (rd<<0));
emit2(scaledd);
return;
}
}
/* Otherwise we need the full 48 bits. */
newrelo(expr->typ, RELOVC4|RELPC);
/* VC4 relocations store the PC-relative delta into the
* destination section in the instruction data. The linker will
* massage this, and scale it appropriately. */
if (!fitx(d, 27))
toobig();
emit2(B16(11100111,00000000) | (opcode<<5) | (rd<<0));
emit4((31<<27) | maskx(d, 27));
break;
}
}
} }
/* Common code for handling addcmp: merge in as much of expr as will fit to /* Common code for handling addcmp: merge in as much of expr as will fit to
@ -420,33 +381,23 @@ void mem_address_instr(quad opcode, int rd, struct expr_t* expr)
static void branch_addcmp_common(quad opcode, int bits, struct expr_t* expr) static void branch_addcmp_common(quad opcode, int bits, struct expr_t* expr)
{ {
quad type = expr->typ & S_TYP; quad type = expr->typ & S_TYP;
int d;
switch (pass) if (type != DOTTYP)
{ serror("can't use this type of branch to jump outside the section");
case 0:
/* Calculate size of instructions only. */
emit2(0); /* The VC4 branch instructions express distance in 2-byte
break; * words. */
case 1: d = (expr->val - DOTVAL-2 + 4);
case 2: if ((pass == 2) && (d > 0) && !(expr->typ & S_DOT))
{ d -= DOTGAIN;
if (type != DOTTYP) d /= 2;
serror("can't use this type of branch to jump outside the section");
/* The VC4 branch instructions express distance in 2-byte if (!fitx(d, bits))
* words. */ serror("target of branch is too far away");
int d = (expr->val - DOTVAL-2 + 4) / 2; emit2(opcode | maskx(d, bits));
if (!fitx(d, bits))
serror("target of branch is too far away");
emit2(opcode | maskx(d, bits));
break;
}
}
} }
void branch_addcmp_reg_reg_instr(int cc, int rd, int ra, int rs, struct expr_t* expr) void branch_addcmp_reg_reg_instr(int cc, int rd, int ra, int rs, struct expr_t* expr)
@ -518,6 +469,10 @@ void lea_address_instr(int rd, struct expr_t* expr)
{ {
quad pc = DOTVAL; quad pc = DOTVAL;
quad type = expr->typ & S_TYP; quad type = expr->typ & S_TYP;
int d = expr->val - pc;
if ((pass == 2) && (d > 0) && !(expr->typ & S_DOT))
d -= DOTGAIN;
if (type == S_ABS) if (type == S_ABS)
serror("can't use absolute addresses here"); serror("can't use absolute addresses here");