FPROUND - variable flag offset

This commit is contained in:
tevador 2019-01-11 10:52:12 +01:00
parent e487092f07
commit c02ee4291d
5 changed files with 20 additions and 8 deletions

View File

@ -12,6 +12,7 @@ There are 31 unique instructions divided into 3 groups:
## Integer instructions
There are 22 integer instructions. They are divided into 3 classes (MATH, DIV, SHIFT) with different B operand selection rules.
|# opcodes|instruction|class|signed|A width|B width|C|C width|
|-|-|-|-|-|-|-|-|
|12|ADD_64|MATH|no|64|64|`A + B`|64|
@ -55,7 +56,7 @@ The shift/rotate instructions use just the bottom 6 bits of the `B` operand (`im
There are 5 floating point instructions. All floating point instructions are vector instructions that operate on two packed double precision floating point values.
|# opcodes|instruction|C|
|-|-|-|-|
|-|-|-|
|20|FPADD|`A + B`|
|20|FPSUB|`A - B`|
|22|FPMUL|`A * B`|

View File

@ -9,6 +9,7 @@ The encoding of each 128-bit instruction word is following:
There are 256 opcodes, which are distributed between 3 groups of instructions. There are 31 distinct operations (each operation can be encoded using multiple opcodes - for example opcodes `0x00` to `0x0d` correspond to integer addition).
**Table 1: Instruction groups**
|group|# operations|# opcodes||
|---------|-----------------|----|-|
|integer (IA)|22|144|56.3%|
@ -31,8 +32,8 @@ The `A.LOC.W` flag determines the address width when reading operand A from the
**Table 3: Operand A read address width**
|`A.LOC.W`|address width (W)
|---------|-|-|
|`A.LOC.W`|address width (W)|
|---------|-|
|0|15 bits (256 KiB)|
|1-3|11 bits (16 KiB)|
@ -125,8 +126,8 @@ The `C.LOC.W` flag determines the address width when writing operand C to the sc
**Table 10: Operand C write address width**
|`C.LOC.W`|address width (W)
|---------|-|-|
|`C.LOC.W`|address width (W)|
|---------|-|
|0|15 bits (256 KiB)|
|1-3|11 bits (16 KiB)|

View File

@ -466,7 +466,9 @@ namespace RandomX {
void AssemblyGeneratorX86::h_FPROUND(Instruction& instr, int i) {
genar(instr, i);
asmCode << "\tmov rcx, rax" << std::endl;
asmCode << "\tshl eax, 13" << std::endl;
int rotate = (13 - (instr.imm8 & 63)) & 63;
if (rotate != 0)
asmCode << "\trol rax, " << rotate << std::endl;
asmCode << "\tand eax, 24576" << std::endl;
asmCode << "\tor eax, 40896" << std::endl;
asmCode << "\tmov dword ptr [rsp - 8], eax" << std::endl;

View File

@ -574,7 +574,15 @@ namespace RandomX {
void JitCompilerX86::h_FPROUND(Instruction& instr, int i) {
genar(instr);
emit(0x00250de0c1c88b48); //mov rcx,rax; shl eax,0xd
emitByte(0x48);
emit(uint16_t(0xc88b)); //mov rcx,rax
int rotate = (13 - (instr.imm8 & 63)) & 63;
if (rotate != 0) {
emitByte(0x48);
emit(uint16_t(0xc0c1)); //rol rax
emitByte(rotate);
}
emit(uint16_t(0x0025));
emit(0x00009fc00d000060); //and eax,0x6000; or eax,0x9fc0
emit(0x2454ae0ff8244489); //ldmxcsr DWORD PTR [rsp-0x8]
emitByte(0xf8);

View File

@ -8859,7 +8859,7 @@ rx_body_509:
and ecx, 2047
mov rax, qword ptr [rsi+rcx*8]
mov rcx, rax
shl eax, 13
rol rax, 34
and eax, 24576
or eax, 40896
mov dword ptr [rsp - 8], eax