diff options
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/vmgen.nim | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/compiler/vmgen.nim b/compiler/vmgen.nim index dbb63e166..84577bb22 100644 --- a/compiler/vmgen.nim +++ b/compiler/vmgen.nim @@ -70,6 +70,9 @@ proc echoCode*(c: PCtx, start=0) {.deprecated.} = echo buf proc gABC(ctx: PCtx; n: PNode; opc: TOpcode; a, b, c: TRegister = 0) = + ## Takes the registers `b` and `c`, applies the operation `opc` to them, and + ## stores the result into register `a` + ## The node is needed for debug information assert opc.ord < 255 let ins = (opc.uint32 or (a.uint32 shl 8'u32) or (b.uint32 shl 16'u32) or @@ -78,6 +81,10 @@ proc gABC(ctx: PCtx; n: PNode; opc: TOpcode; a, b, c: TRegister = 0) = ctx.debug.add(n.info) proc gABI(c: PCtx; n: PNode; opc: TOpcode; a, b: TRegister; imm: BiggestInt) = + # Takes the `b` register and the immediate `imm`, appies the operation `opc`, + # and stores the output value into `a`. + # `imm` is signed and must be within [-127, 128] + assert(imm >= -127 and imm <= 128) let ins = (opc.uint32 or (a.uint32 shl 8'u32) or (b.uint32 shl 16'u32) or (imm+byteExcess).uint32 shl 24'u32).TInstr @@ -85,6 +92,9 @@ proc gABI(c: PCtx; n: PNode; opc: TOpcode; a, b: TRegister; imm: BiggestInt) = c.debug.add(n.info) proc gABx(c: PCtx; n: PNode; opc: TOpcode; a: TRegister = 0; bx: int) = + # Applies `opc` to `bx` and stores it into register `a` + # `bx` must be signed and in the range [-32767, 32768] + assert(bx >= -32767 and bx <= 32768) let ins = (opc.uint32 or a.uint32 shl 8'u32 or (bx+wordExcess).uint32 shl 16'u32).TInstr c.code.add(ins) |