From 99bcce0d89b8a9aa9a1cc481b41be101c07d8bdf Mon Sep 17 00:00:00 2001
From: Harald Anlauf <anlauf@gmx.de>
Date: Thu, 16 Jan 2025 20:23:06 +0100
Subject: libfortran: fix conversion of UNSIGNED(kind=16) to decimal in output
 [PR118406]

	PR libfortran/118406

libgfortran/ChangeLog:

	* runtime/string.c (gfc_itoa): Handle unsigned integers larger than
	(10^19 * 2^64).

gcc/testsuite/ChangeLog:

	* gfortran.dg/unsigned_write.f90: New test.
---
 gcc/testsuite/gfortran.dg/unsigned_write.f90 | 40 ++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)
 create mode 100644 gcc/testsuite/gfortran.dg/unsigned_write.f90

(limited to 'gcc')

diff --git a/gcc/testsuite/gfortran.dg/unsigned_write.f90 b/gcc/testsuite/gfortran.dg/unsigned_write.f90
new file mode 100644
index 0000000..903c212
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/unsigned_write.f90
@@ -0,0 +1,40 @@
+! { dg-do  run }
+! This is a libgfortran (runtime library) test, need to run only once!
+!
+! { dg-require-effective-target fortran_integer_16 }
+! { dg-additional-options "-funsigned" }
+!
+! PR libfortran/118406 - printing large UNSIGNED(kind=16) crashes
+
+program print_large_unsigned
+  unsigned(16), parameter :: u16_max =      huge(0U_16)
+  unsigned(16), parameter :: u8_max  = uint(huge(0U_8),16)        ! UINT64_MAX
+  unsigned(16), parameter :: ten19   = uint(10_8 ** 18,16)*10U_16 ! 10**19
+  character(42) :: s
+
+  ! Reference: signed integer
+  write(s,*)       huge(0_16)
+  if (adjustl (s) /= "170141183460469231731687303715884105727") stop 1
+
+  ! Same value as unsigned
+  write(s,*) uint (huge(0_16),16)
+  if (adjustl (s) /= "170141183460469231731687303715884105727") stop 2
+
+  ! Extreme and intermediate values
+  write(s,*) u16_max
+  if (adjustl (s) /= "340282366920938463463374607431768211455") stop 3
+
+  write(s,*) (u16_max - 3U_16) / 4U_16 * 3U_16
+  if (adjustl (s) /= "255211775190703847597530955573826158589") stop 4
+
+  ! Test branches of implementation in string.c::gfc_itoa
+  write(s,*) u8_max * ten19
+  if (adjustl (s) /= "184467440737095516150000000000000000000") stop 5
+
+  write(s,*) u8_max * ten19 - 1U_16
+  if (adjustl (s) /= "184467440737095516149999999999999999999") stop 6
+
+  write(s,*) u8_max * ten19 + 1U_16
+  if (adjustl (s) /= "184467440737095516150000000000000000001") stop 7
+
+end
-- 
cgit v1.1