added cpuTime to VM (#12346)

* added cpuTime to VM

* Hide VM-time cpuTime() behind --benchmarkVM flag

compiler/commands.nim

@@ -792,6 +792,8 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
       discard "the default"
     else:
       localError(conf, info, "unknown Nim version; currently supported values are: {1.0}")
+  of "benchmarkvm":
+    processOnOffSwitchG(conf, {optBenchmarkVM}, arg, pass, info)
   of "":
     conf.projectName = "-"
   else:

compiler/options.nim

@@ -84,6 +84,7 @@ type                          # please make sure we have under 32 options
     optNimV2
     optMultiMethods
     optNimV019
+    optBenchmarkVM            # Enables cpuTime() in the VM
 
   TGlobalOptions* = set[TGlobalOption]
 

compiler/vmops.nim

@@ -16,6 +16,7 @@ from math import sqrt, ln, log10, log2, exp, round, arccos, arcsin,
 from os import getEnv, existsEnv, dirExists, fileExists, putEnv, walkDir, getAppFilename
 from md5 import getMD5
 from sighashes import symBodyDigest
+from times import cpuTime
 
 from hashes import hash
 
@@ -25,6 +26,9 @@ template mathop(op) {.dirty.} =
 template osop(op) {.dirty.} =
   registerCallback(c, "stdlib.os." & astToStr(op), `op Wrapper`)
 
+template timesop(op) {.dirty.} =
+  registerCallback(c, "stdlib.times." & astToStr(op), `op Wrapper`)
+
 template systemop(op) {.dirty.} =
   registerCallback(c, "stdlib.system." & astToStr(op), `op Wrapper`)
 
@@ -194,3 +198,9 @@ proc registerAdditionalOps*(c: PCtx) =
 
   registerCallback c, "stdlib.hashes.hashVmImplByte", hashVmImplByte
   registerCallback c, "stdlib.hashes.hashVmImplChar", hashVmImplByte
+
+  if optBenchmarkVM in c.config.globalOptions:
+    wrap0(cpuTime, timesop)
+  else:
+    proc cpuTime(): float = 5.391245e-44  # Randomly chosen
+    wrap0(cpuTime, timesop)

doc/advopt.txt

@@ -129,3 +129,4 @@ Advanced options:
   --profiler:on|off         enable profiling; requires `import nimprof`, and
                             works better with `--stackTrace:on`
                             see also https://nim-lang.github.io/Nim/estp.html
+  --benchmarkVM:on|off      enable benchmarking of VM code with cpuTime()