Avoid unnecesssary remainder calculations

Detail:
  s/HeapSort, s/vdu/vdugrafc, s/vdu/vduswis - Avoid unnecessary remainder calculations in DivRem macro
  s/PMF/i2cutils, s/PMF/osword - Make use of DivRem's ability to accept a constant as the divisor
Admin:
  Tested on Cortex-A15


Version 5.35, 4.79.2.318. Tagged as 'Kernel-5_35-4_79_2_318'

VersionASM

@@ -13,11 +13,11 @@
                         GBLS    Module_ComponentPath
 Module_MajorVersion     SETS    "5.35"
 Module_Version          SETA    535
-Module_MinorVersion     SETS    "4.79.2.317"
-Module_Date             SETS    "26 Apr 2016"
-Module_ApplicationDate  SETS    "26-Apr-16"
+Module_MinorVersion     SETS    "4.79.2.318"
+Module_Date             SETS    "08 May 2016"
+Module_ApplicationDate  SETS    "08-May-16"
 Module_ComponentName    SETS    "Kernel"
 Module_ComponentPath    SETS    "castle/RiscOS/Sources/Kernel"
-Module_FullVersion      SETS    "5.35 (4.79.2.317)"
-Module_HelpVersion      SETS    "5.35 (26 Apr 2016) 4.79.2.317"
+Module_FullVersion      SETS    "5.35 (4.79.2.318)"
+Module_HelpVersion      SETS    "5.35 (08 May 2016) 4.79.2.318"
                         END

VersionNum

@@ -5,19 +5,19 @@
  *
  */
 #define Module_MajorVersion_CMHG        5.35
-#define Module_MinorVersion_CMHG        4.79.2.317
-#define Module_Date_CMHG                26 Apr 2016
+#define Module_MinorVersion_CMHG        4.79.2.318
+#define Module_Date_CMHG                08 May 2016
 
 #define Module_MajorVersion             "5.35"
 #define Module_Version                  535
-#define Module_MinorVersion             "4.79.2.317"
-#define Module_Date                     "26 Apr 2016"
+#define Module_MinorVersion             "4.79.2.318"
+#define Module_Date                     "08 May 2016"
 
-#define Module_ApplicationDate          "26-Apr-16"
+#define Module_ApplicationDate          "08-May-16"
 
 #define Module_ComponentName            "Kernel"
 #define Module_ComponentPath            "castle/RiscOS/Sources/Kernel"
 
-#define Module_FullVersion              "5.35 (4.79.2.317)"
-#define Module_HelpVersion              "5.35 (26 Apr 2016) 4.79.2.317"
+#define Module_FullVersion              "5.35 (4.79.2.318)"
+#define Module_HelpVersion              "5.35 (08 May 2016) 4.79.2.318"
 #define Module_LibraryVersionInfo       "5:35"

s/HeapSort

@@ -239,7 +239,7 @@ h8      STR     hs_R, [hs_array, hs_i, LSL #2] ; R(i) = R
         STR     r14, [r5]               ; mark item 'done'
 
         SUB     r5, r7, r1              ; r14 := index of next item (r8 pres.)
-        DivRem  r14, r5, r8, r0         ; r5,r0 corrupt
+        DivRem  r14, r5, r8, r0, norem  ; r5,r0 corrupt
         ADD     r5, r2, r14, LSL #2     ; r5 -> next item
  [ DebugHeapSort
  DREG r7, "  next block "

s/PMF/i2cutils

@@ -61,11 +61,10 @@ E2ROMAddress32K         *       &a6     ; 24CS256 device - 32K (top 2K possibly
 ;
 
 HexToBCD ROUT
-        Push    "R1,R2, R14"
-        MOV     R1, #10
-        DivRem  R2, R0, R1, R14                 ; R2=R0 DIV 10; R0=R0 MOD 10
+        Push    "R2, R14"
+        DivRem  R2, R0, #10, R14                ; R2=R0 DIV 10; R0=R0 MOD 10
         ADD     R0, R0, R2, LSL #4
-        Pull    "R1,R2, PC"
+        Pull    "R2, PC"
 
 ; *****************************************************************************
 ;

s/PMF/osword

@@ -659,8 +659,7 @@ OsWord0F ROUT
         Pull    "r0,r2,r3,r5"           ; hours, day of month, month, year
         ADD     sp, sp, #8              ; junk day of week, day of year
         ADD     sp, sp, r10             ; and string on stack
-        MOV     r4, #100
-        DivRem  r6, r5, r4, r14         ; r5 = Year (lo), r6 = Year (hi)
+        DivRem  r6, r5, #100, r14       ; r5 = Year (lo), r6 = Year (hi)
 
         BL      SetTime                 ; also updates 5-byte RealTime
 

s/vdu/vdugrafc

@@ -254,28 +254,15 @@ GenEllParm
 
         MOV R0,R7                       ;Setup SliceCnt
 
-       ;MOV R7,R0                       ;Div R5,R5,R0 using R7,R9,R10
         MOV R9,R5,LSL #16
-; *****Change made by DJS
-; Use new DivRem macro, not old DIVREM
-; Original code was:
-;        DIVREM R5,R9,R7,R10             ;R5 := totalshear/ellipseheight
-        DivRem R5,R9,R7,R10             ;R5 := totalshear/ellipseheight
-; *****End of change made by DJS
-
-       ;BIC R5,R5,#&FF                  ;Slugg accuracy for compatability?
+        DivRem R5,R9,R7,R10,norem       ;R5 := totalshear/ellipseheight
 
         CMP R8,#0
         RSBLT R5,R5,#0                  ;Correct for negative slope
 
         MOV R7,R0                       ;Div R6,R6,R0 using R7,R9,R10
         MOV R9,R6,LSL #8
-; *****Change made by DJS
-; Use new DivRem macro, not old DIVREM
-; Original code was:
-;        DIVREM R6,R9,R7,R10             ;R6 := slicewidth/ellipseheight
-        DivRem R6,R9,R7,R10             ;R6 := slicewidth/ellipseheight
-; *****End of change made by DJS
+        DivRem R6,R9,R7,R10,norem       ;R6 := slicewidth/ellipseheight
 
 
 ; R5 holds shear per scanline

s/vdu/vduswis

@@ -119,10 +119,10 @@ SWIReadVduVariables                     ; alternative symbol used for init'ing
         MOVEQ   R3, #0                  ; else 0
 
         SUB     R7, R0, R2              ; R7 = width-1-(width reduction)
-        DivRem  R0, R7, R4, R2          ; R0 = (width-(1 or sizex))DIV spacex
+        DivRem  R0, R7, R4, R2, norem   ; R0 = (width-(1 or sizex))DIV spacex
 
         SUB     R7, R3, R1              ; R7 = height-(1-height reduction)
-        DivRem  R1, R7, R5, R3          ; R1 = (height-(1 or sizey))DIV spacey
+        DivRem  R1, R7, R5, R3, norem   ; R1 = (height-(1 or sizey))DIV spacey
 32
         TST     R6, #8                  ; are X and Y reversed ?
         EORNE   R0, R0, R1              ; yes, then swap