diff --git a/compiler/ccgexprs.nim b/compiler/ccgexprs.nim
index 27c8f607e7..1a73f8fbb9 100644
--- a/compiler/ccgexprs.nim
+++ b/compiler/ccgexprs.nim
@@ -3677,7 +3677,10 @@ proc expr(p: BProc, n: PNode, d: var TLoc) =
   of nkProcDef, nkFuncDef, nkMethodDef, nkConverterDef:
     if n[genericParamsPos].kind == nkEmpty:
       var prc = n[namePos].sym
-      if delayedCodegen(p.module):
+      if optCompress in p.config.globalOptions:
+        if prc.magic in generatedMagics:
+          genProc(p.module, prc)
+      elif delayedCodegen(p.module):
         if p.module.alive.contains(prc.itemId.item) and
             prc.magic in generatedMagics:
           genProc(p.module, prc)
diff --git a/compiler/ccgtypes.nim b/compiler/ccgtypes.nim
index e58c1439b5..a7b29b9c87 100644
--- a/compiler/ccgtypes.nim
+++ b/compiler/ccgtypes.nim
@@ -608,7 +608,7 @@ proc genProcParams(m: BModule; t: PType, rettype: var Rope, params: var Builder,
         else:
           descKind = dkRefParam
       if isCompileTimeOnly(param.typ): continue
-      ensureMutable param
+      #ensureMutable param
       fillParamName(m, param)
       fillLoc(param.locImpl, locParam, t.n[i],
               param.paramStorageLoc)
diff --git a/compiler/cgendata.nim b/compiler/cgendata.nim
index b82962898f..479babb0b9 100644
--- a/compiler/cgendata.nim
+++ b/compiler/cgendata.nim
@@ -119,7 +119,7 @@ type
     mapping*: Rope             # the generated mapping file (if requested)
     modules*: seq[BModule]     # list of all compiled modules
     modulesClosed*: seq[BModule] # list of the same compiled modules, but in the order they were closed
-    forwardedProcs*: seq[PSym] # proc:s that did not yet have a body
+    forwardedProcs*: seq[PSym] # procs that did not yet have a body
     generatedHeader*: BModule
     typeInfoMarker*: TypeCacheWithOwner
     typeInfoMarkerV2*: TypeCacheWithOwner
diff --git a/lib/std/private/digitsutils.nim b/lib/std/private/digitsutils.nim
index f2d0d25cba..989a049967 100644
--- a/lib/std/private/digitsutils.nim
+++ b/lib/std/private/digitsutils.nim
@@ -29,6 +29,8 @@ const
 #   doAssert res == digits100
 #   ```
 
+{.push checks: off, stackTrace: off.}
+
 proc utoa2Digits*(buf: var openArray[char]; pos: int; digits: uint32) {.inline.} =
   buf[pos] = digits100[2 * digits]
   buf[pos+1] = digits100[2 * digits + 1]
@@ -114,3 +116,5 @@ proc addInt*(result: var string; x: int64) {.enforceNoRaises.} =
 
 proc addInt*(result: var string; x: int) {.inline, enforceNoRaises.} =
   addInt(result, int64(x))
+
+{.pop.}
diff --git a/lib/system/chcks.nim b/lib/system/chcks.nim
index 1a7d7f0a90..1653e824ca 100644
--- a/lib/system/chcks.nim
+++ b/lib/system/chcks.nim
@@ -9,8 +9,6 @@
 
 # Implementation of some runtime checks.
 include system/indexerrors
-when defined(nimPreviewSlimSystem):
-  import std/formatfloat
 
 proc raiseRangeError(val: BiggestInt) {.compilerproc, noinline.} =
   when hostOS == "standalone":
@@ -53,12 +51,6 @@ proc raiseRangeErrorI(i, a, b: BiggestInt) {.compilerproc, noinline.} =
   else:
     sysFatal(RangeDefect, "value out of range: " & $i & " notin " & $a & " .. " & $b)
 
-proc raiseRangeErrorF(i, a, b: float) {.compilerproc, noinline.} =
-  when defined(standalone):
-    sysFatal(RangeDefect, "value out of range")
-  else:
-    sysFatal(RangeDefect, "value out of range: " & $i & " notin " & $a & " .. " & $b)
-
 proc raiseRangeErrorU(i, a, b: uint64) {.compilerproc, noinline.} =
   # todo: better error reporting
   sysFatal(RangeDefect, "value out of range")
@@ -97,16 +89,6 @@ proc chckRangeU(i, a, b: uint64): uint64 {.compilerproc.} =
     result = 0
     sysFatal(RangeDefect, "value out of range")
 
-proc chckRangeF(x, a, b: float): float =
-  if x >= a and x <= b:
-    return x
-  else:
-    result = 0.0
-    when hostOS == "standalone":
-      sysFatal(RangeDefect, "value out of range")
-    else:
-      sysFatal(RangeDefect, "value out of range: ", $x)
-
 proc chckNil(p: pointer) =
   if p == nil:
     sysFatal(NilAccessDefect, "attempt to write to a nil address")
@@ -164,3 +146,32 @@ when not defined(nimV2):
 when defined(nimV2):
   proc raiseObjectCaseTransition() {.compilerproc.} =
     sysFatal(FieldDefect, "assignment to discriminant changes object branch")
+
+when defined(nimPreviewSlimSystem):
+  import std/formatfloat
+
+when not defined(nimPreviewSlimSystem):
+  import std/formatfloat
+  export addFloat
+
+  func `$`*(x: float | float32): string =
+    ## Outplace version of `addFloat`.
+    result = ""
+    result.addFloat(x)
+
+
+proc raiseRangeErrorF(i, a, b: float) {.compilerproc, noinline.} =
+  when defined(standalone):
+    sysFatal(RangeDefect, "value out of range")
+  else:
+    sysFatal(RangeDefect, "value out of range: " & $i & " notin " & $a & " .. " & $b)
+
+proc chckRangeF(x, a, b: float): float =
+  if x >= a and x <= b:
+    return x
+  else:
+    result = 0.0
+    when hostOS == "standalone":
+      sysFatal(RangeDefect, "value out of range")
+    else:
+      sysFatal(RangeDefect, "value out of range: ", $x)
diff --git a/lib/system/dollars.nim b/lib/system/dollars.nim
index e33d6bbc8a..2025d42964 100644
--- a/lib/system/dollars.nim
+++ b/lib/system/dollars.nim
@@ -5,15 +5,6 @@ runnableExamples:
 
 import std/private/[digitsutils, miscdollars]
 
-when not defined(nimPreviewSlimSystem):
-  import std/formatfloat
-  export addFloat
-
-  func `$`*(x: float | float32): string =
-    ## Outplace version of `addFloat`.
-    result = ""
-    result.addFloat(x)
-
 template addIntAlias(T: typedesc) =
   proc `$`*(x: T): string {.raises: [].} =
     ## Outplace version of `addInt`.
diff --git a/lib/system/memory.nim b/lib/system/memory.nim
index 156773c484..c6c3cb3ab0 100644
--- a/lib/system/memory.nim
+++ b/lib/system/memory.nim
@@ -5,7 +5,7 @@ const useLibC = not defined(nimNoLibc)
 when useLibC:
   import ansi_c
 
-proc nimCopyMem*(dest, source: pointer, size: Natural) {.nonReloadable, compilerproc, inline.} =
+proc nimCopyMem*(dest, source: pointer, size: Natural) {.nonReloadable, compilerproc, inline, enforceNoRaises.} =
   when useLibC:
     c_memcpy(dest, source, cast[csize_t](size))
   else:
@@ -16,7 +16,7 @@ proc nimCopyMem*(dest, source: pointer, size: Natural) {.nonReloadable, compiler
       d[i] = s[i]
       inc i
 
-proc nimSetMem*(a: pointer, v: cint, size: Natural) {.nonReloadable, inline.} =
+proc nimSetMem*(a: pointer, v: cint, size: Natural) {.nonReloadable, inline, enforceNoRaises.} =
   when useLibC:
     c_memset(a, v, cast[csize_t](size))
   else:
@@ -27,10 +27,10 @@ proc nimSetMem*(a: pointer, v: cint, size: Natural) {.nonReloadable, inline.} =
       a[i] = v
       inc i
 
-proc nimZeroMem*(p: pointer, size: Natural) {.compilerproc, nonReloadable, inline.} =
+proc nimZeroMem*(p: pointer, size: Natural) {.compilerproc, nonReloadable, inline, enforceNoRaises.} =
   nimSetMem(p, 0, size)
 
-proc nimCmpMem*(a, b: pointer, size: Natural): cint {.compilerproc, nonReloadable, inline.} =
+proc nimCmpMem*(a, b: pointer, size: Natural): cint {.compilerproc, nonReloadable, inline, enforceNoRaises.} =
   when useLibC:
     c_memcmp(a, b, cast[csize_t](size))
   else:
@@ -42,7 +42,7 @@ proc nimCmpMem*(a, b: pointer, size: Natural): cint {.compilerproc, nonReloadabl
       if d != 0: return d
       inc i
 
-proc nimCStrLen*(a: cstring): int {.compilerproc, nonReloadable, inline.} =
+proc nimCStrLen*(a: cstring): int {.compilerproc, nonReloadable, inline, enforceNoRaises.} =
   if a.isNil: return 0
   when useLibC:
     cast[int](c_strlen(a))