fix type-stability bugs in Ryu code (JuliaLang#52781)

Fixes JuliaLang#52749.

base/ryu/exp.jl

@@ -7,7 +7,7 @@ function writeexp(buf, pos, v::T,
  pos = append_sign(x, plus, space, buf, pos)
 
  # special cases
- if x == 0
+ if iszero(x)
  @inbounds buf[pos] = UInt8('0')
  pos += 1
  if precision > 0 && !trimtrailingzeros
@@ -42,7 +42,7 @@ function writeexp(buf, pos, v::T,
  mant = bits & MANTISSA_MASK
  exp = Int((bits >> 52) & EXP_MASK)
 
- if exp == 0
+ if iszero(exp)
  e2 = 1 - 1023 - 52
  m2 = mant
  else
@@ -51,7 +51,7 @@ function writeexp(buf, pos, v::T,
  end
  nonzero = false
  precision += 1
- digits = 0
+ digits = zero(UInt32)
  printedDigits = 0
  availableDigits = 0
  e = 0
@@ -64,14 +64,14 @@ function writeexp(buf, pos, v::T,
  j = p10bits - e2
  #=@inbounds=# mula, mulb, mulc = POW10_SPLIT[POW10_OFFSET[idx + 1] + i + 1]
  digits = mulshiftmod1e9(m2 << 8, mula, mulb, mulc, j + 8)
- if printedDigits != 0
+ if !iszero(printedDigits)
  if printedDigits + 9 > precision
  availableDigits = 9
  break
  end
  pos = append_nine_digits(digits, buf, pos)
  printedDigits += 9
- elseif digits != 0
+ elseif !iszero(digits)
  availableDigits = decimallength(digits)
  e = i * 9 + availableDigits - 1
  if availableDigits > precision
@@ -93,26 +93,26 @@ function writeexp(buf, pos, v::T,
  i -= 1
  end
  end
- if e2 < 0 && availableDigits == 0
+ if e2 < 0 && iszero(availableDigits)
  idx = div(-e2, 16)
- i = MIN_BLOCK_2[idx + 1]
+ i = Int(MIN_BLOCK_2[idx + 1])
  while i < 200
  j = 120 + (-e2 - 16 * idx)
  p = POW10_OFFSET_2[idx + 1] + i - MIN_BLOCK_2[idx + 1]
  if p >= POW10_OFFSET_2[idx + 2]
- digits = 0
+ digits = zero(UInt32)
  else
  #=@inbounds=# mula, mulb, mulc = POW10_SPLIT_2[p + 1]
  digits = mulshiftmod1e9(m2 << 8, mula, mulb, mulc, j + 8)
  end
- if printedDigits != 0
+ if !iszero(printedDigits)
  if printedDigits + 9 > precision
  availableDigits = 9
  break
  end
  pos = append_nine_digits(digits, buf, pos)
  printedDigits += 9
- elseif digits != 0
+ elseif !iszero(digits)
  availableDigits = decimallength(digits)
  e = -(i + 1) * 9 + availableDigits - 1
  if availableDigits > precision
@@ -135,14 +135,14 @@ function writeexp(buf, pos, v::T,
  end
  end
  maximum = precision - printedDigits
- if availableDigits == 0
- digits = 0
+ if iszero(availableDigits)
+ digits = zero(UInt32)
  end
- lastDigit = 0
+ lastDigit = zero(UInt32)
  if availableDigits > maximum
  for k = 0:(availableDigits - maximum - 1)
- lastDigit = digits % 10
- digits = div(digits, 10)
+ lastDigit = digits % UInt32(10)
+ digits = div(digits, UInt32(10))
  end
  end
  roundUp = 0
@@ -159,8 +159,8 @@ function writeexp(buf, pos, v::T,
  end
  roundUp = trailingZeros ? 2 : 1
  end
- if printedDigits != 0
- if digits == 0
+ if !iszero(printedDigits)
+ if iszero(digits)
  for _ = 1:maximum
  @inbounds buf[pos] = UInt8('0')
  pos += 1
@@ -180,7 +180,7 @@ function writeexp(buf, pos, v::T,
  end
  end
  end
- if roundUp != 0
+ if !iszero(roundUp)
  roundPos = pos
  while true
  roundPos -= 1
@@ -197,7 +197,7 @@ function writeexp(buf, pos, v::T,
  roundUp = 1
  continue
  else
- if roundUp == 2 && UInt8(c) % 2 == 0
+ if roundUp == 2 && iseven(c)
  break
  end
  @inbounds buf[roundPos] = c + 1
@@ -224,7 +224,7 @@ function writeexp(buf, pos, v::T,
  pos += 1
  end
  if e >= 100
- c = e % 10
+ c = (e % 10) % UInt8
  @inbounds d100 = DIGIT_TABLE16[div(e, 10) + 1]
  @inbounds buf[pos] = d100 % UInt8
  @inbounds buf[pos + 1] = (d100 >> 0x8) % UInt8

stdlib/Printf/test/runtests.jl

@@ -1145,4 +1145,7 @@ end
  @test_throws Printf.InvalidFormatStringError Printf.Format("%z")
 end
 
+# issue #52749
+@test @sprintf("%.160g", 1.38e-23) == "1.380000000000000060010582465734078799297660966782642624395399644741944111814291318296454846858978271484375e-23"
+
 end # @testset "Printf"