7272 - snapshot: printing floats in decimal

I've made some progress to where I can print whole integers right. But
this whole approach of mixing decimals with binary exponents is going to
be super confusing. I need to bite the bullet and just use decimal exponents.

1 files changed, 339 insertions, 4 deletions

diff --git a/408print-float.mu b/408print-float.mu
index e1c916f6..626a098a 100644
--- a/408print-float.mu
+++ b/408print-float.mu
@@ -1,4 +1,7 @@
-# quick-n-dirty way to print out floats in hex
+# quick-n-dirty way to print out floats
+
+######## In hex, following C's %a format
+# https://www.exploringbinary.com/hexadecimal-floating-point-constants
 
 # examples:
 #   0.5 = 0x3f000000 = 0011| 1111 | 0000 | 0000 | 0000 | 0000 | 0000 | 0000
@@ -24,6 +27,63 @@ fn test-print-float-normal {
   check-screen-row screen, 1, "1.000000P-01 ", "F - test-print-float-normal"
 }
 
+fn test-print-float-normal-2 {
+  var screen-on-stack: screen
+  var screen/esi: (addr screen) <- address screen-on-stack
+  initialize-screen screen, 5, 0x20  # 32 columns should be more than enough
+  # print 0.25
+  var one/eax: int <- copy 1
+  var quarter/xmm0: float <- convert one
+  var four/eax: int <- copy 4
+  var four-f/xmm1: float <- convert four
+  quarter <- divide four-f
+  print-float screen, quarter
+  #
+  check-screen-row screen, 1, "1.000000P-02 ", "F - test-print-float-normal-2"
+}
+
+fn test-print-float-normal-3 {
+  var screen-on-stack: screen
+  var screen/esi: (addr screen) <- address screen-on-stack
+  initialize-screen screen, 5, 0x20  # 32 columns should be more than enough
+  # print 0.75
+  var three/eax: int <- copy 3
+  var three-quarters/xmm0: float <- convert three
+  var four/eax: int <- copy 4
+  var four-f/xmm1: float <- convert four
+  three-quarters <- divide four-f
+  print-float screen, three-quarters
+  #
+  check-screen-row screen, 1, "1.800000P-01 ", "F - test-print-float-normal-3"
+}
+
+fn test-print-float-normal-4 {
+  var screen-on-stack: screen
+  var screen/esi: (addr screen) <- address screen-on-stack
+  initialize-screen screen, 5, 0x20  # 32 columns should be more than enough
+  # print 0.1
+  var one/eax: int <- copy 1
+  var tenth/xmm0: float <- convert one
+  var ten/eax: int <- copy 0xa
+  var ten-f/xmm1: float <- convert ten
+  tenth <- divide ten-f
+  print-float screen, tenth
+  #
+  check-screen-row screen, 1, "1.99999aP-04 ", "F - test-print-float-normal-4"
+}
+
+fn test-print-float-integer {
+  var screen-on-stack: screen
+  var screen/esi: (addr screen) <- address screen-on-stack
+  initialize-screen screen, 5, 0x20  # 32 columns should be more than enough
+  # print 1
+  var one/eax: int <- copy 1
+  var one-f/xmm0: float <- convert one
+  print-float screen, one-f
+  #
+  check-screen-row screen, 1, "1.000000P00 ", "F - test-print-float-integer"
+}
+
 fn test-print-float-zero {
   var screen-on-stack: screen
   var screen/esi: (addr screen) <- address screen-on-stack
@@ -119,7 +179,8 @@ fn print-float screen: (addr screen), n: float {
   var exponent/ecx: int <- copy bits
   exponent <- shift-right 0x17  # 23 bits of mantissa
   exponent <- and 0xff
-  compare exponent, 0xff
+  exponent <- subtract 0x7f
+  compare exponent, 0x80
   {
     break-if-!=
     print-string screen, "Nan"
@@ -135,7 +196,7 @@ fn print-float screen: (addr screen), n: float {
   }
   $print-float:leading-digit: {
     # check for subnormal numbers
-    compare exponent, 0
+    compare exponent, -0x7f
     {
       break-if-!=
       print-string screen, "0."
@@ -147,10 +208,10 @@ fn print-float screen: (addr screen), n: float {
   }
   var mantissa/ebx: int <- copy bits
   mantissa <- and 0x7fffff
+  mantissa <- shift-left 1  # pad to whole nibbles
   print-int32-hex-bits screen, mantissa, 0x18
   # print exponent
   print-string screen, "P"
-  exponent <- subtract 0x7f
   compare exponent, 0
   {
     break-if->=
@@ -167,3 +228,277 @@ fn print-float screen: (addr screen), n: float {
 #? #?   test-print-float-normal
 #?   return 0
 #? }
+
+######## In decimal
+
+fn test-print-float-decimal-normal {
+  var screen-on-stack: screen
+  var screen/esi: (addr screen) <- address screen-on-stack
+  initialize-screen screen, 5, 0x20  # 32 columns should be more than enough
+  # print 0.5
+  var one/eax: int <- copy 1
+  var half/xmm0: float <- convert one
+  var two/eax: int <- copy 2
+  var two-f/xmm1: float <- convert two
+  half <- divide two-f
+  print-float-decimal screen, half
+  #
+  check-screen-row screen, 1, "1P-1 ", "F - test-print-float-decimal-normal"
+}
+
+fn test-print-float-decimal-normal-2 {
+  var screen-on-stack: screen
+  var screen/esi: (addr screen) <- address screen-on-stack
+  initialize-screen screen, 5, 0x20  # 32 columns should be more than enough
+  # print 0.25
+  var one/eax: int <- copy 1
+  var quarter/xmm0: float <- convert one
+  var four/eax: int <- copy 4
+  var four-f/xmm1: float <- convert four
+  quarter <- divide four-f
+  print-float-decimal screen, quarter
+  #
+  check-screen-row screen, 1, "1P-2 ", "F - test-print-float-decimal-normal-2"
+}
+
+fn test-print-float-decimal-normal-3 {
+  var screen-on-stack: screen
+  var screen/esi: (addr screen) <- address screen-on-stack
+  initialize-screen screen, 5, 0x20  # 32 columns should be more than enough
+  # print 0.75
+  var three/eax: int <- copy 3
+  var three-quarters/xmm0: float <- convert three
+  var four/eax: int <- copy 4
+  var four-f/xmm1: float <- convert four
+  three-quarters <- divide four-f
+  print-float-decimal screen, three-quarters
+  #
+  check-screen-row screen, 1, "3P-2 ", "F - test-print-float-decimal-normal-3"
+}
+
+# print whole integers without decimals
+fn test-print-float-decimal-integer {
+  var screen-on-stack: screen
+  var screen/esi: (addr screen) <- address screen-on-stack
+  initialize-screen screen, 5, 0x20  # 32 columns should be more than enough
+  # print 1
+  var one/eax: int <- copy 1
+  var one-f/xmm0: float <- convert one
+  print-float-decimal screen, one-f
+  #
+  check-screen-row screen, 1, "1 ", "F - test-print-float-decimal-integer"
+}
+
+fn test-print-float-decimal-integer-2 {
+  var screen-on-stack: screen
+  var screen/esi: (addr screen) <- address screen-on-stack
+  initialize-screen screen, 5, 0x20  # 32 columns should be more than enough
+  # print 2
+  var two/eax: int <- copy 2
+  var two-f/xmm0: float <- convert two
+  print-float-decimal screen, two-f
+  #
+  check-screen-row screen, 1, "2 ", "F - test-print-float-decimal-integer-2"
+}
+
+fn test-print-float-decimal-integer-3 {
+  var screen-on-stack: screen
+  var screen/esi: (addr screen) <- address screen-on-stack
+  initialize-screen screen, 5, 0x20  # 32 columns should be more than enough
+  # print 10
+  var ten/eax: int <- copy 0xa
+  var ten-f/xmm0: float <- convert ten
+  print-float-decimal screen, ten-f
+  #
+  check-screen-row screen, 1, "10 ", "F - test-print-float-decimal-integer-3"
+}
+
+fn test-print-float-decimal-integer-4 {
+  var screen-on-stack: screen
+  var screen/esi: (addr screen) <- address screen-on-stack
+  initialize-screen screen, 5, 0x20  # 32 columns should be more than enough
+  # print -10
+  var minus-ten/eax: int <- copy -0xa
+  var minus-ten-f/xmm0: float <- convert minus-ten
+  print-float-decimal screen, minus-ten-f
+  #
+  check-screen-row screen, 1, "-10 ", "F - test-print-float-decimal-integer-4"
+}
+
+fn test-print-float-decimal-zero {
+  var screen-on-stack: screen
+  var screen/esi: (addr screen) <- address screen-on-stack
+  initialize-screen screen, 5, 0x20  # 32 columns should be more than enough
+  # print 0
+  var zero: float
+  print-float-decimal screen, zero
+  #
+  check-screen-row screen, 1, "0 ", "F - test-print-float-decimal-zero"
+}
+
+fn test-print-float-decimal-negative-zero {
+  var screen-on-stack: screen
+  var screen/esi: (addr screen) <- address screen-on-stack
+  initialize-screen screen, 5, 0x20  # 32 columns should be more than enough
+  # print 0
+  var n: int
+  copy-to n, 0x80000000
+  var negative-zero/xmm0: float <- reinterpret n
+  print-float-decimal screen, negative-zero
+  #
+  check-screen-row screen, 1, "-0 ", "F - test-print-float-decimal-negative-zero"
+}
+
+fn test-print-float-decimal-infinity {
+  var screen-on-stack: screen
+  var screen/esi: (addr screen) <- address screen-on-stack
+  initialize-screen screen, 5, 0x20  # 32 columns should be more than enough
+  # print
+  var n: int
+  #          0|11111111|00000000000000000000000
+  #          0111|1111|1000|0000|0000|0000|0000|0000
+  copy-to n, 0x7f800000
+  var infinity/xmm0: float <- reinterpret n
+  print-float-decimal screen, infinity
+  #
+  check-screen-row screen, 1, "Inf ", "F - test-print-float-decimal-infinity"
+}
+
+fn test-print-float-decimal-negative-infinity {
+  var screen-on-stack: screen
+  var screen/esi: (addr screen) <- address screen-on-stack
+  initialize-screen screen, 5, 0x20  # 32 columns should be more than enough
+  # print
+  var n: int
+  copy-to n, 0xff800000
+  var negative-infinity/xmm0: float <- reinterpret n
+  print-float-decimal screen, negative-infinity
+  #
+  check-screen-row screen, 1, "-Inf ", "F - test-print-float-decimal-negative-infinity"
+}
+
+fn test-print-float-decimal-not-a-number {
+  var screen-on-stack: screen
+  var screen/esi: (addr screen) <- address screen-on-stack
+  initialize-screen screen, 5, 0x20  # 32 columns should be more than enough
+  # print
+  var n: int
+  copy-to n, 0xffffffff  # exponent must be all 1's, and mantissa must be non-zero
+  var negative-infinity/xmm0: float <- reinterpret n
+  print-float-decimal screen, negative-infinity
+  #
+  check-screen-row screen, 1, "Nan ", "F - test-print-float-decimal-not-a-number"
+}
+
+fn print-float-decimal screen: (addr screen), n: float {
+  # - special names
+  var bits/eax: int <- reinterpret n
+  compare bits, 0
+  {
+    break-if-!=
+    print-string screen, "0"
+    return
+  }
+  compare bits, 0x80000000
+  {
+    break-if-!=
+    print-string screen, "-0"
+    return
+  }
+  compare bits, 0x7f800000
+  {
+    break-if-!=
+    print-string screen, "Inf"
+    return
+  }
+  compare bits, 0xff800000
+  {
+    break-if-!=
+    print-string screen, "-Inf"
+    return
+  }
+  var exponent/ecx: int <- copy bits
+  exponent <- shift-right 0x17  # 23 bits of mantissa
+  exponent <- and 0xff
+#?   print-string 0, "exponent0: "
+#?   print-int32-hex 0, exponent
+#?   print-string 0, "\n"
+  exponent <- subtract 0x7f
+  compare exponent, 0x80
+  {
+    break-if-!=
+    print-string screen, "Nan"
+    return
+  }
+  # - regular numbers
+  var sign/edx: int <- copy bits
+  sign <- shift-right 0x1f
+  {
+    compare sign, 1
+    break-if-!=
+    print-string screen, "-"
+  }
+  var mantissa/ebx: int <- copy bits
+  mantissa <- and 0x7fffff
+#?   print-string 0, "mantissa0: "
+#?   print-int32-hex 0, mantissa
+#?   print-string 0, "\n"
+  # whole integers
+  compare exponent, 0
+  {
+    break-if-<
+#?     print-string 0, "mantissa: "
+#?     print-int32-hex 0, mantissa
+#?     print-string 0, "\n"
+#?     print-string 0, "exponent: "
+#?     print-int32-hex 0, exponent
+#?     print-string 0, "\n"
+    var tmp/eax: int <- copy mantissa
+    tmp <- shift-left 9  # move to MSB
+    tmp <- repeated-shift-left tmp, exponent
+    compare tmp, 0
+    break-if-!=
+    var result/eax: int <- copy mantissa
+    result <- or 0x00800000  # insert implicit 1
+    result <- repeated-shift-left result, exponent
+    result <- shift-right 0x17  # 24 bits
+#?     print-string 0, "result: "
+#?     print-int32-hex 0, result
+#?     print-string 0, "\n"
+    print-int32-decimal screen, result
+    return
+  }
+  $print-float-decimal:leading-digit: {
+    # check for subnormal numbers
+    compare exponent, -0x7f
+    {
+      break-if-!=
+      print-string screen, "0"
+      exponent <- increment
+      break $print-float-decimal:leading-digit
+    }
+    # normal numbers
+    print-string screen, "1"
+  }
+#?   var mantissa/ebx: int <- copy bits
+#?   mantissa <- and 0x7fffff
+  compare mantissa, 0
+  {
+    break-if-=
+    print-string screen, "."
+    # TODO
+    mantissa <- shift-left 1  # whole number of nibbles
+    print-int32-hex-bits screen, mantissa, 0x18
+  }
+  # print exponent if necessary
+  compare exponent, 0
+  break-if-=
+  print-string screen, "P"
+  print-int32-decimal screen, exponent
+}
+
+#? fn main -> _/ebx: int {
+#?   run-tests
+#? #?   test-print-float-decimal-integer
+#?   return 0
+#? }