Hash functions

CMakeLists.txt

@@ -21,6 +21,7 @@ if(CMAKE_Fortran_COMPILER_ID STREQUAL GNU)
   endif()
   add_compile_options(-fimplicit-none)
   add_compile_options(-ffree-line-length-132)
+  add_compile_options(-fno-range-check)
   add_compile_options(-Wall)
   add_compile_options(-Wextra)
   add_compile_options(-Wimplicit-procedure)

Makefile.manual

@@ -1,7 +1,7 @@
 # Fortran stdlib Makefile
 
 FC ?= gfortran
-FFLAGS ?= -Wall -Wextra -Wimplicit-interface -fPIC -g -fcheck=all
+FFLAGS ?= -Wall -Wextra -Wimplicit-interface -fPIC -g -fcheck=all -fno-range-check
 FYPPFLAGS ?=
 
 export FC

doc/specs/index.md

@@ -14,6 +14,8 @@ This is and index/directory of the specifications (specs) for each new module/fe
  - [ascii](./stdlib_ascii.html) - Procedures for handling ASCII characters
  - [bitsets](./stdlib_bitsets.html) - Bitset data types and procedures
  - [error](./stdlib_error.html) - Catching and handling errors
+ - [hash\_functions](./stdlib_has_functions.html) - Hashing integer
+   vectors or character strings
  - [IO](./stdlib_io.html) - Input/output helper & convenience
  - [kinds](./stdlib_kinds.html) - Kind parameters
  - [linalg](./stdlib_linalg.html) - Linear Algebra

src/CMakeLists.txt

@@ -2,6 +2,14 @@
 
 # Create a list of the files to be preprocessed
 set(fppFiles
+    stdlib_32_bit_fnv_hashes.fypp
+    stdlib_32_bit_hash_functions.fypp
+    stdlib_32_bit_nmhashes.fypp 
+    stdlib_32_bit_water_hashes.fypp 
+    stdlib_64_bit_fnv_hashes.fypp 
+    stdlib_64_bit_hash_functions.fypp 
+    stdlib_64_bit_pengy_hashes.fypp 
+    stdlib_64_bit_spookyv2_hashes.fypp 
     stdlib_ascii.fypp
     stdlib_bitsets.fypp
     stdlib_bitsets_64.fypp

src/Makefile.manual

@@ -1,4 +1,12 @@
 SRCFYPP = \
+        stdlib_32_bit_fnv_hashes.fypp \
+        stdlib_32_bit_hash_functions.fypp \
+        stdlib_32_bit_nmhashes.fypp \
+        stdlib_32_bit_water_hashes.fypp \
+        stdlib_64_bit_fnv_hashes.fypp \
+        stdlib_64_bit_hash_functions.fypp \
+        stdlib_64_bit_pengy_hashes.fypp \
+        stdlib_64_bit_spookyv2_hashes.fypp \
         stdlib_ascii.fypp \
         stdlib_bitsets_64.fypp \
         stdlib_bitsets_large.fypp \
@@ -74,6 +82,22 @@ $(SRCGEN): %.f90: %.fypp common.fypp
 
 # Fortran module dependencies
 f18estop.o: stdlib_error.o
+stdlib_32_bit_fnv_hashes.o: \
+   stdlib_32_bit_hash_functions.o
+stdlib_32_bit_hash_functions.o: \
+   stdlib_kinds.o
+stdlib_32_bit_nmhashes.o: \
+   stdlib_32_bit_hash_functions.o
+stdlib_32_bit_water_hashes.o: \
+   stdlib_32_bit_hash_functions.o
+stdlib_64_bit_fnv_hashes.o: \
+   stdlib_64_bit_hash_functions.o
+stdlib_64_bit_hash_functions.o: \
+   stdlib_kinds.o
+stdlib_64_bit_pengy_hashes.o: \
+   stdlib_64_bit_hash_functions.o
+stdlib_64_bit_spookyv2_hashes.o: \
+   stdlib_64_bit_hash_functions.o
 stdlib_ascii.o: stdlib_kinds.o
 stdlib_bitsets.o: stdlib_kinds.o
 stdlib_bitsets_64.o: stdlib_bitsets.o

src/stdlib_32_bit_fnv_hashes.fypp

@@ -0,0 +1,126 @@
+!!------------------------------------------------------------------------------
+!! `FNV_1_HASH` and  `FNV_1A_Hash` are translations to Fortran 2008 of the
+!! `FNV-1` and `FNV-1a` hash functions of Glenn Fowler, Landon Curt Noll,
+!! and Phong Vo, that has been released into the public domain. Permission
+!! has been granted, by Landon Curt Noll, for the use of these algorithms
+!! in the Fortran Standard Library. A description of these functions is
+!! available at https://en.wikipedia.org/wiki/Fowler–Noll–Vo_hash_function.
+!!------------------------------------------------------------------------------
+
+!#! Integer kinds to be considered during templating
+#:set INT_KINDS = ["int16", "int32", "int64"]
+
+submodule(stdlib_32_bit_hash_functions) stdlib_32_bit_fnv_hashes
+!! An implementation of the FNV hashes 1 and 1a of Glenn Fowler, Landon Curt
+!! Noll, and Kiem-Phong-Vo,
+!! https://en.wikipedia.org/wiki/Fowler–Noll–Vo_hash_function
+    implicit none
+
+    integer(int_hash), parameter ::                  &
+        offset_basis = int( z'811C9DC5', int_hash ), &
+        prime        = int( z'01000193', int_hash )
+
+contains
+
+    pure module function int8_fnv_1( key ) result(hash_code)
+!! The original FNV-1 8-bit key algorithm.
+        integer(int8), intent(in)     :: key(:)
+        integer(int_hash)             :: hash_code
+
+        integer(int64) :: i
+
+        hash_code = offset_basis
+        do i=1_int64, size(key, kind=int64)
+            hash_code = hash_code * prime
+            if ( little_endian ) then
+                hash_code = ieor( hash_code, &
+                                  transfer( [key(i), 0_int8, 0_int8, 0_int8], &
+                                            0_int_hash ) )
+            else
+                hash_code = ieor( hash_code, &
+                                  transfer( [0_int8, 0_int8, 0_int8, key(i)], &
+                                            0_int_hash ) )
+            end if
+        end do
+
+    end function int8_fnv_1
+
+
+#:for k1 in INT_KINDS
+    pure module function ${k1}$_fnv_1( key ) result(hash_code)
+! A ${k1}$ array key wrapper for the FNV-1 algorithm.
+        integer(${k1}$), intent(in) :: key(:)
+        integer(int_hash)           :: hash_code
+
+        hash_code = int8_fnv_1( transfer( key, 0_int8,                      &
+                                          bytes_${k1}$*                     &
+                                          size( key, kind=int64 ) ) )
+
+    end function ${k1}$_fnv_1
+
+#:endfor
+
+
+    pure module function character_fnv_1( key ) result(hash_code)
+! A default character key wrapper for the FNV-1 algorithm.
+        character(*), intent(in)      :: key
+        integer(int_hash)             :: hash_code
+
+        hash_code = int8_fnv_1( transfer( key,                           &
+                                          0_int8,                        &
+                                          bytes_char*                    &
+                                          len(key, kind=int64) ) )
+
+    end function character_fnv_1
+
+
+    pure module function int8_fnv_1a( key ) result(hash_code)
+!! The original FNV-1a 8-bit key algorithm.
+        integer(int8), intent(in)     :: key(:)
+        integer(int_hash)             :: hash_code
+
+        integer(int64) :: i
+
+        hash_code = offset_basis
+        do i=1_int64, size(key, kind=int64)
+            if ( little_endian ) then
+                hash_code = ieor( hash_code, &
+                                  transfer( [key(i), 0_int8, 0_int8, 0_int8],  &
+                                            0_int_hash ) )
+            else
+                hash_code = ieor( hash_code, &
+                                  transfer( [0_int8, 0_int8, 0_int8, key(i)], &
+                                            0_int_hash ) )
+            end if
+            hash_code = hash_code * prime
+        end do
+
+    end function int8_fnv_1a
+
+
+#:for k1 in INT_KINDS
+    pure module function ${k1}$_fnv_1a( key ) result(hash_code)
+! A ${k1}$ array key wrapper for the FNV-1a algorithm.
+        integer(${k1}$), intent(in)   :: key(:)
+        integer(int_hash)             :: hash_code
+
+        hash_code = int8_fnv_1a( transfer( key, 0_int8,                   &
+                                           bytes_${k1}$*                  &
+                                           size(key, kind=int64)) )
+
+    end function ${k1}$_fnv_1a
+
+#:endfor
+
+    pure module function character_fnv_1a( key ) result(hash_code)
+! A default character key wrapper for the FNV-1 algorithm.
+        character(*), intent(in)      :: key
+        integer(int_hash)             :: hash_code
+
+        hash_code = int8_fnv_1a( transfer( key, 0_int8,                   &
+                                           (bits_char/bits_int8)*         &
+                                           len(key, kind=int64) ) )
+
+    end function character_fnv_1a
+
+end submodule stdlib_32_bit_fnv_hashes