Position markers for stack subeffect isolation

4 files changed, 158 insertions, 4 deletions

diff --git a/TODO b/TODO
index 78e5e34..769449c 100644
--- a/TODO
+++ b/TODO
@@ -1,6 +1,8 @@
+* allow stack manipulation at site of position tags
 * apply the trace extractor to non-tail situations
 * implement the GC-based function opcode forwarding
-* allow stack manipulation at site of uppermost ARRAYMARKER
+* inline loop similar to each
+* forward scope-cannot-escape information
 * utf8
 * regex substitution
 * asm-based regex engine
@@ -8,6 +10,7 @@
 * txt .consume .u sollte nicht negative Zahlen liefern
   * evtl. BigNums bauen und die Int-Funktionen entsprechend machen
 * trigonometrics
+* document new , functions
 
 * testsuite (incl. coverage test)
 
diff --git a/compiler/elymasGlobal.ey b/compiler/elymasGlobal.ey
index 3fc309f..2ecf6b9 100644
--- a/compiler/elymasGlobal.ey
+++ b/compiler/elymasGlobal.ey
@@ -13,6 +13,7 @@
 
   1 ==ARRAYMARKER
   2 ==QUOTEMARKER
+  3 ==POSITIONMARKER
 
   <
     [
@@ -1084,6 +1085,89 @@
       :retn
     ]] /eyrange defv
 
+    # put a position marker onto the stack
+    [[
+      /rax :popqReg
+      POSITIONMARKER :pushqImm32
+      /rax :pushqReg
+      :retn
+    ]] /ey, defv
+
+    # delete topmost position marker and shift stack
+    [[
+      /rbx :popqReg
+      /rsp /rsi :movqRegReg
+      POSITIONMARKER /rax :movqImmReg
+      /rdx :popqReg
+      /rax /rdx :cmpqRegReg
+      /done :jzLbl8
+      @loop
+      8 /rsi :addqImm8Reg
+      /rdx /rsi :xchgqRegMem
+      /rax /rdx :cmpqRegReg
+      /loop :jnzLbl8
+      @done
+      /rbx :pushqReg
+      :retn
+    ]] /ey,-- defv
+
+    # move topmost position marker left/upwards and shift stack
+    [[
+      /rbx :popqReg
+      /rsp /rsi :movqRegReg
+      POSITIONMARKER /rax :movqImmReg
+      /rdx :popqReg
+      /rax /rdx :cmpqRegReg
+      /done :jzLbl8
+      @loop
+      8 /rsi :addqImm8Reg
+      /rdx /rsi :xchgqRegMem
+      /rax /rdx :cmpqRegReg
+      /loop :jnzLbl8
+      @done
+      /rdx 8 /rsi :movqRegMemDisp8
+      /rbx :pushqReg
+      :retn
+    ]] /ey--, defv
+
+    # access element left (higher up in stack) of topmost position marker
+    [[
+      /rbx :popqReg
+      /rsp /rdi :movqRegReg
+      POSITIONMARKER /rax :movqImmReg
+      /rcx /rcx :xorqRegReg
+      /rcx :decqReg
+      :repnz :scasq
+      /rdi :pushqMem
+      /rbx :pushqReg
+      :retn
+    ]] /ey_, defv
+
+    # access element right (lower in stack) of topmost position marker
+    [[
+      /rbx :popqReg
+      /rsp /rdi :movqRegReg
+      POSITIONMARKER /rax :movqImmReg
+      /rcx /rcx :xorqRegReg
+      /rcx :decqReg
+      :repnz :scasq
+      16 neg /rdi :pushqMemDisp8
+      /rbx :pushqReg
+      :retn
+    ]] /ey,_ defv
+
+    # delete stack up to and including topmost position marker
+    [[
+      /rbx :popqReg
+      POSITIONMARKER /rax :movqImmReg
+      @loop
+      /rdx :popqReg
+      /rax /rdx :cmpqRegReg
+      /loop :jnzLbl8
+      /rbx :pushqReg
+      :retn
+    ]] /ey,--- defv
+
     # create a new scope capturing the current one
     [
       ::INITIALSCOPESIZE /rdi :movqImmReg
diff --git a/doc/notes b/doc/notes
index a01083d..d4d1a6c 100644
--- a/doc/notes
+++ b/doc/notes
@@ -70,11 +70,11 @@ $: <open>
 %: <open>
 &: <open>
 ': type assignment
-(: tuple begin
-): tuple end
+(: <open>
+): <open>
 *: apply function
 +: <open>
-,: <open>
+,: position markers
 -: stack manipulation
 .: field dereference
 /: stringify
diff --git a/elymas/lib/sys/opt.ey b/elymas/lib/sys/opt.ey
index ca3f37a..01cf0ff 100644
--- a/elymas/lib/sys/opt.ey
+++ b/elymas/lib/sys/opt.ey
@@ -6,6 +6,7 @@
   > /ops sys .asm .defv
 
   1 ==ARRAYMARKER # FIXME unify with elymasGlobal.ey
+  3 ==POSITIONMARKER # FIXME unify with elymasGlobal.ey
   4 ==INITIALSCOPESIZE # FIXME take this from the compiler directory
 
   sys .asm .ops ==:sysasmops
@@ -345,6 +346,7 @@
     /quoted /range "''" ".?" ".?'" ".|" ";"
     /keys /dom /add /and /band /bor /bxor /div /eq /ge /gt /le /lt
     /mod /mul /neq /or /sub /udiv /umod /xor /bnot /neg /not
+    "," ",--" "--," "_," ",_" ",---"
   ] { | ::rawCodeAddress } [ 0 ] [ 0 ] '' * ==:SCOPEIGNORANTFUNCTIONS
   [
     "|" "=" /def
@@ -1981,6 +1983,71 @@
               ARRAYMARKER :pushqImm32
             ] ] =entry
           }
+          { action CALL eq { 1 entry * "," | ::rawCodeAddress eq }' andif }' {
+            [ NATIVENOSCOPE [
+              POSITIONMARKER :pushqImm32
+            ] ] =entry
+          }
+          { action CALL eq { 1 entry * ",--" | ::rawCodeAddress eq }' andif }' {
+            [ NATIVENOSCOPE [[
+              /rsp /rsi :movqRegReg
+              POSITIONMARKER /rax :movqImmReg
+              /rdx :popqReg
+              /rax /rdx :cmpqRegReg
+              /done :jzLbl8
+              @loop
+              8 /rsi :addqImm8Reg
+              /rdx /rsi :xchgqRegMem
+              /rax /rdx :cmpqRegReg
+              /loop :jnzLbl8
+              @done
+            ]] ] =entry
+          }
+          { action CALL eq { 1 entry * "--," | ::rawCodeAddress eq }' andif }' {
+            [ NATIVENOSCOPE [[
+              /rsp /rsi :movqRegReg
+              POSITIONMARKER /rax :movqImmReg
+              /rdx :popqReg
+              /rax /rdx :cmpqRegReg
+              /done :jzLbl8
+              @loop
+              8 /rsi :addqImm8Reg
+              /rdx /rsi :xchgqRegMem
+              /rax /rdx :cmpqRegReg
+              /loop :jnzLbl8
+              @done
+              /rdx 8 /rsi :movqRegMemDisp8
+            ]] ] =entry
+          }
+          { action CALL eq { 1 entry * "_," | ::rawCodeAddress eq }' andif }' {
+            [ NATIVENOSCOPE [[
+              /rsp /rdi :movqRegReg
+              POSITIONMARKER /rax :movqImmReg
+              /rcx /rcx :xorqRegReg
+              /rcx :decqReg
+              :repnz :scasq
+              /rdi :pushqMem
+            ]] ] =entry
+          }
+          { action CALL eq { 1 entry * ",_" | ::rawCodeAddress eq }' andif }' {
+            [ NATIVENOSCOPE [[
+              /rsp /rdi :movqRegReg
+              POSITIONMARKER /rax :movqImmReg
+              /rcx /rcx :xorqRegReg
+              /rcx :decqReg
+              :repnz :scasq
+              16 neg /rdi :pushqMemDisp8
+            ]] ] =entry
+          }
+          { action CALL eq { 1 entry * ",---" | ::rawCodeAddress eq }' andif }' {
+            [ NATIVENOSCOPE [[
+              POSITIONMARKER /rax :movqImmReg
+              @loop
+              /rdx :popqReg
+              /rax /rdx :cmpqRegReg
+              /loop :jnzLbl8
+            ]] ] =entry
+          }
         ] conds
 
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