Fix rounding issues introduced by SANE bug workarounds.

The lrint functions could give the wrong result for negative numbers in upward/downward rounding modes. Casts to comp could also have different rounding behavior.
2021-11-30 20:19:57 -06:00 · 2021-11-30 20:19:57 -06:00 · b01800ff77
parent b6690c4826
commit b01800ff77
3 changed files with 19 additions and 4 deletions
--- a/fpextra.asm
+++ b/fpextra.asm
@ -81,6 +81,12 @@ fpextra  private                        dummy segment
 ****************************************************************
 *
 ~CompPrecision start
+         tsc                            round to integer
+         clc
+         adc     #4
+         pea     0
+         pha
+         FRINTX
         lda     4+8,s
         pha                            save original sign
         asl     a                      force sign to positive
--- a/fpextra.macros
+++ b/fpextra.macros
@ -34,3 +34,9 @@
 LDX #$090A
 JSL $E10000
 MEND
+ MACRO
+&LAB FRINTX
+&LAB PEA $0014
+ LDX #$090A
+ JSL $E10000
+ MEND
--- a/math2.asm
+++ b/math2.asm
@ -1136,17 +1136,20 @@ lrintl   entry
         csubroutine (10:x),0

         pei   x+8                      save sign of x
-         asl   x+8                      x = abs(x)
-         lsr   x+8

-         tdc                            convert to integer
+         tdc
         clc
         adc   #x
         pea   0
         pha
         pea   0
         pha
-         FX2C
+         pea   0
+         pha
+         FRINTX                         round x to integer
+         asl   x+8                      x = abs(x)
+         lsr   x+8
+         FX2C                           convert to comp

         lda   x+4                      if x is out of range of long
         ora   x+6