diff options
Diffstat (limited to 'execution.e')
| -rw-r--r-- | execution.e | 53 |
1 files changed, 52 insertions, 1 deletions
diff --git a/execution.e b/execution.e index 20064af..66f04d1 100644 --- a/execution.e +++ b/execution.e @@ -236,6 +236,21 @@ ~ (output memory start, current output point ~ -- output memory start, current output point) : output-cold-start + ~ : blank-line + ~ : blank-line + ~ : ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + ~ : ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + ~ : ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + ~ : ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + ~ : blank-line + ~ : This is the start of the cold-start routine, which is the first code + ~ : of any kind the executable runs. It has the responsibility of creating + ~ : the Forth execution environment, then invoking the warm-start routine, + ~ : which is defined below. + ~ : blank-line + ~ : blank-line + ~ : indent + current-offset L' cold-start set-label cld ~ clear the DF flag @@ -389,7 +404,9 @@ ~ We are about to set up rsi, we did rbp already, and rsp came to us ~ already set up. That's all that "next" needs, so take it away! L@' warm-start L@' origin + :rsi mov-reg64-imm64 - pack-next ; + pack-next + ~ : deindent + ; ~ Routine warm-start @@ -403,6 +420,35 @@ ~ (output buffer start, output point, input string pointer, delimiter pointer ~ -- output buffer start, output point) : output-warm-start + ~ : blank-line + ~ : blank-line + ~ : ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + ~ : ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + ~ : ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + ~ : ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + ~ : blank-line + ~ : This is the start of the warm-start routine, which is the first Forth + ~ : code the executable runs, after the cold-start routine has created the + ~ : Forth execution environment. + ~ : + ~ : It does some initial setup here at the top; then the vast bulk of it + ~ : is actually the log-load routine, directly included; then finally there + ~ : is a small amount of finishing work done at the tail end of the + ~ : warm-start routine. + ~ : + ~ : The routine's body is interpreted Forth code, meaning that it is an + ~ : an array of pointers to the codewords of Forth words, occasionally + ~ : interspersed with literal values. + ~ : + ~ : The codeword pointers were located by using the label system, which + ~ : means the labels they reference must have been defined somewhere else, + ~ : normally by the label transform. The label-transformed code normally + ~ : occurs after the warm-start routine in the executable, which means these + ~ : are forward references to words defined far below. + ~ : blank-line + ~ : blank-line + ~ : indent + ~ While it's not actually a requirement that codeword pointers be ~ word-aligned, it's highly likely that it helps performance. (Whether it ~ does is up to Intel's microcode.) @@ -498,6 +544,10 @@ log-load-transform ~ (output buffer start, output point) + ~ : blank-line + ~ : We're now done with the log-load routine; the next little bit of code + ~ : here is the final bit of the warm-start routine. + ~ Now everything we need has been added to the log and we're almost ready ~ to jump into it. It's inconvenient for code under the log-load transform ~ to interact with the label system, so if we want to point @@ -511,6 +561,7 @@ ~ Get rid of that heap pointer on the stack, we're finally done with it! L@' drop offset-to-target-address-space pack64 L@' execute offset-to-target-address-space pack64 + ~ : deindent ; |