Improve handling of "#0" in VFP/NEON assembler

Where an instruction/encoding only allows a zero value, matching against
the assembly line is performed by looking for an actual "#0" character
sequence. This means that, unlike other locations where literals are
parsed, it's impossible to use a variable, function, or any other kind
of expression to provide the value.

Change the assembler to detect when a "#0" sequence is being looked for,
and use the numeric expression parser instead. This will make it much
easier to use the zero-shift synonym instructions, since it's common for
programs to use expressions to specify/calculate shift amounts (which
may evaluate to zero in some circumstances)

Version 1.80. Tagged as 'BASIC-1_80'

VFPLib/VFPLib

@@ -263,10 +263,10 @@ DEF PROCvfp_setuplookup
   PROCvfp_addlookup("VCMP{<c>}.<dt> <Sd>,<Sm>"          ,"VCMP,VCMPE A1"                        ,"F32"                   ,"" ,"E=0")
   PROCvfp_addlookup("VCMPE{<c>}.<dt> <Sd>,<Sm>"         ,"VCMP,VCMPE A1"                        ,"F32"                   ,"" ,"E=1")
 
-  PROCvfp_addlookup("VCMP{<c>}.<dt> <Dd>,#0{.0}"        ,"VCMP,VCMPE A2"                        ,"F64"                   ,"" ,"E=0")
-  PROCvfp_addlookup("VCMPE{<c>}.<dt> <Dd>,#0{.0}"       ,"VCMP,VCMPE A2"                        ,"F64"                   ,"" ,"E=1")
-  PROCvfp_addlookup("VCMP{<c>}.<dt> <Sd>,#0{.0}"        ,"VCMP,VCMPE A2"                        ,"F32"                   ,"" ,"E=0")
-  PROCvfp_addlookup("VCMPE{<c>}.<dt> <Sd>,#0{.0}"       ,"VCMP,VCMPE A2"                        ,"F32"                   ,"" ,"E=1")
+  PROCvfp_addlookup("VCMP{<c>}.<dt> <Dd>,#0"            ,"VCMP,VCMPE A2"                        ,"F64"                   ,"" ,"E=0")
+  PROCvfp_addlookup("VCMPE{<c>}.<dt> <Dd>,#0"           ,"VCMP,VCMPE A2"                        ,"F64"                   ,"" ,"E=1")
+  PROCvfp_addlookup("VCMP{<c>}.<dt> <Sd>,#0"            ,"VCMP,VCMPE A2"                        ,"F32"                   ,"" ,"E=0")
+  PROCvfp_addlookup("VCMPE{<c>}.<dt> <Sd>,#0"           ,"VCMP,VCMPE A2"                        ,"F32"                   ,"" ,"E=1")
 
   REM VCEQ/VCGE/VCGT/VCLE/VCLT
   PROCvfp_addlookup("VCEQ.<dt> <Qd>,<Qn>,<Qm>"         ,"VCEQ (register) A1"                    ,"I8,I16,I32"            ,"" ,"")

VersionASM

@@ -9,12 +9,12 @@
                         GBLS    Module_ApplicationDate
                         GBLS    Module_HelpVersion
                         GBLS    Module_ComponentName
-Module_MajorVersion     SETS    "1.79"
-Module_Version          SETA    179
+Module_MajorVersion     SETS    "1.80"
+Module_Version          SETA    180
 Module_MinorVersion     SETS    ""
-Module_Date             SETS    "29 Feb 2020"
-Module_ApplicationDate  SETS    "29-Feb-20"
+Module_Date             SETS    "02 Apr 2020"
+Module_ApplicationDate  SETS    "02-Apr-20"
 Module_ComponentName    SETS    "BASIC"
-Module_FullVersion      SETS    "1.79"
-Module_HelpVersion      SETS    "1.79 (29 Feb 2020)"
+Module_FullVersion      SETS    "1.80"
+Module_HelpVersion      SETS    "1.80 (02 Apr 2020)"
                         END

VersionNum

-/* (1.79)
+/* (1.80)
  *
  * This file is automatically maintained by srccommit, do not edit manually.
  *
  */
-#define Module_MajorVersion_CMHG        1.79
+#define Module_MajorVersion_CMHG        1.80
 #define Module_MinorVersion_CMHG        
-#define Module_Date_CMHG                29 Feb 2020
+#define Module_Date_CMHG                02 Apr 2020
 
-#define Module_MajorVersion             "1.79"
-#define Module_Version                  179
+#define Module_MajorVersion             "1.80"
+#define Module_Version                  180
 #define Module_MinorVersion             ""
-#define Module_Date                     "29 Feb 2020"
+#define Module_Date                     "02 Apr 2020"
 
-#define Module_ApplicationDate          "29-Feb-20"
+#define Module_ApplicationDate          "02-Apr-20"
 
 #define Module_ComponentName            "BASIC"
 
-#define Module_FullVersion              "1.79"
-#define Module_HelpVersion              "1.79 (29 Feb 2020)"
-#define Module_LibraryVersionInfo       "1:79"
+#define Module_FullVersion              "1.80"
+#define Module_HelpVersion              "1.80 (02 Apr 2020)"
+#define Module_LibraryVersionInfo       "1:80"

s/VFP

@@ -521,6 +521,14 @@ VFPmsChar
         TEQ     R0,#"\\"                        ; slash?
         LDREQB  R0,[R9],#1                      ; if yes, get the next char unfiltered
 
+        ; See if this is a literal #0 which we're searching for.
+        ; If it is, parse the input as an expression instead of looking for an
+        ; exact character match.
+        TEQ     R0,#"0"
+        LDREQB  R1,[R9,#-2]
+        TEQEQ   R1,#"#"
+        BEQ     VFPmsc_litzero
+
         LDRB    R1,[AELINE],#1                  ; get next char from input
 
         TEQ     R1,#TVDU                        ; expand tokenised VDU
@@ -644,6 +652,15 @@ VFPmsc_opcode
         BNE     VFPmsc_nomatch                  ; NE = no match...
         B       VFPmsc_match                    ; EQ = match...
 
+        ; An expression which must evaluate to zero
+VFPmsc_litzero
+        STR     R14,[R13,#-4]!
+        BL      VFPop_expr
+        LDR     R14,[R13],#4
+        TEQ     R0,#0
+        BNE     VFPmsc_nomatch
+        B       VFPmsc_match
+
         ; ***************************************
         ; ** Read Op-Code from Pattern into R0 **
         ; ***************************************