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Fixes a bit shift issue in an MPI constant
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Redefines TWO_GIG_LIMIT to be INT32_MAX instead of 1 << 31, which
fixes an issue revealed by compiling with -Wshift-overflow.
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@derobins
derobins committed Oct 29, 2020
1 parent 6c0f954 commit 1e93bbc
Showing 1 changed file with 14 additions and 14 deletions.
28 changes: 14 additions & 14 deletions src/H5mpi.c
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Original file line number Diff line number Diff line change
Expand Up @@ -25,15 +25,15 @@
/****************/
/* Local Macros */
/****************/
#define TWO_GIG_LIMIT (1 << 31)
#define TWO_GIG_LIMIT INT32_MAX
#ifndef H5_MAX_MPI_COUNT
#define H5_MAX_MPI_COUNT (1 << 30)
#endif

/*******************/
/* Local Variables */
/*******************/
static hsize_t bigio_count = H5_MAX_MPI_COUNT;
static hsize_t bigio_count_g = H5_MAX_MPI_COUNT;

/*-------------------------------------------------------------------------
* Function: H5_mpi_set_bigio_count
Expand All @@ -42,7 +42,7 @@ static hsize_t bigio_count = H5_MAX_MPI_COUNT;
* when we utilize derived datatypes. This is of
* particular interest for allowing nightly testing
*
* Return: The current/previous value of bigio_count.
* Return: The current/previous value of bigio_count_g.
*
* Programmer: Richard Warren, March 10, 2017
*
Expand All @@ -51,10 +51,10 @@ static hsize_t bigio_count = H5_MAX_MPI_COUNT;
hsize_t
H5_mpi_set_bigio_count(hsize_t new_count)
{
hsize_t orig_count = bigio_count;
hsize_t orig_count = bigio_count_g;

if ((new_count > 0) && (new_count < (hsize_t)TWO_GIG_LIMIT)) {
bigio_count = new_count;
bigio_count_g = new_count;
}
return orig_count;
} /* end H5_mpi_set_bigio_count() */
Expand All @@ -63,9 +63,9 @@ H5_mpi_set_bigio_count(hsize_t new_count)
* Function: H5_mpi_get_bigio_count
*
* Purpose: Allow other HDF5 library functions to access
* the current value for bigio_count.
* the current value for bigio_count_g.
*
* Return: The current/previous value of bigio_count.
* Return: The current/previous value of bigio_count_g.
*
* Programmer: Richard Warren, October 7, 2019
*
Expand All @@ -74,7 +74,7 @@ H5_mpi_set_bigio_count(hsize_t new_count)
hsize_t
H5_mpi_get_bigio_count(void)
{
return bigio_count;
return bigio_count_g;
}

/*-------------------------------------------------------------------------
Expand Down Expand Up @@ -471,8 +471,8 @@ H5_mpio_create_large_type(hsize_t num_elements, MPI_Aint stride_bytes, MPI_Datat
FUNC_ENTER_NOAPI(FAIL)

/* Calculate how many Big MPI datatypes are needed to represent the buffer */
num_big_types = (int)(num_elements / bigio_count);
leftover = (hsize_t)num_elements - (hsize_t)num_big_types * bigio_count;
num_big_types = (int)(num_elements / bigio_count_g);
leftover = (hsize_t)num_elements - (hsize_t)num_big_types * bigio_count_g;
H5_CHECKED_ASSIGN(remaining_bytes, int, leftover, hsize_t);

/* Create a contiguous datatype of size equal to the largest
Expand All @@ -481,11 +481,11 @@ H5_mpio_create_large_type(hsize_t num_elements, MPI_Aint stride_bytes, MPI_Datat
* use type_hvector to create the type with the displacement provided
*/
if (0 == stride_bytes) {
if (MPI_SUCCESS != (mpi_code = MPI_Type_contiguous((int)bigio_count, old_type, &inner_type)))
if (MPI_SUCCESS != (mpi_code = MPI_Type_contiguous((int)bigio_count_g, old_type, &inner_type)))
HMPI_GOTO_ERROR(FAIL, "MPI_Type_contiguous failed", mpi_code)
} /* end if */
else if (MPI_SUCCESS !=
(mpi_code = MPI_Type_create_hvector((int)bigio_count, 1, stride_bytes, old_type, &inner_type)))
(mpi_code = MPI_Type_create_hvector((int)bigio_count_g, 1, stride_bytes, old_type, &inner_type)))
HMPI_GOTO_ERROR(FAIL, "MPI_Type_create_hvector failed", mpi_code)

/* Create a contiguous datatype of the buffer (minus the remaining < 2GB part)
Expand All @@ -510,7 +510,7 @@ H5_mpio_create_large_type(hsize_t num_elements, MPI_Aint stride_bytes, MPI_Datat
HMPI_GOTO_ERROR(FAIL, "MPI_Type_contiguous failed", mpi_code)
} /* end if */
else if (MPI_SUCCESS != (mpi_code = MPI_Type_create_hvector(
(int)(num_elements - (hsize_t)num_big_types * bigio_count), 1,
(int)(num_elements - (hsize_t)num_big_types * bigio_count_g), 1,
stride_bytes, old_type, &leftover_type)))
HMPI_GOTO_ERROR(FAIL, "MPI_Type_create_hvector failed", mpi_code)

Expand All @@ -529,7 +529,7 @@ H5_mpio_create_large_type(hsize_t num_elements, MPI_Aint stride_bytes, MPI_Datat
block_len[0] = 1;
block_len[1] = 1;
disp[0] = 0;
disp[1] = (old_extent + stride_bytes) * num_big_types * (MPI_Aint)bigio_count;
disp[1] = (old_extent + stride_bytes) * num_big_types * (MPI_Aint)bigio_count_g;

if (MPI_SUCCESS != (mpi_code = MPI_Type_create_struct(2, block_len, disp, type, new_type)))
HMPI_GOTO_ERROR(FAIL, "MPI_Type_create_struct failed", mpi_code)
Expand Down

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