diff --git a/hl/src/H5TB.c b/hl/src/H5TB.c
index 842e52b9e69..f94dc26cc5c 100644
--- a/hl/src/H5TB.c
+++ b/hl/src/H5TB.c
@@ -3185,7 +3185,7 @@ H5TB_create_type(hid_t loc_id, const char *dset_name, size_t type_size, const si
     if (H5TBget_table_info(loc_id, dset_name, &nfields, NULL) < 0)
         goto out;
 
-    if (NULL == (fnames = (char **)calloc(sizeof(char *), (size_t)nfields)))
+    if (NULL == (fnames = (char **)calloc((size_t)nfields, sizeof(char *))))
         goto out;
 
     for (i = 0; i < nfields; i++)
diff --git a/test/hyperslab.c b/test/hyperslab.c
index 24cef142712..c407facf18a 100644
--- a/test/hyperslab.c
+++ b/test/hyperslab.c
@@ -985,7 +985,7 @@ test_array_fill(size_t lo, size_t hi)
     TESTING(s);
 
     /* Initialize */
-    if (NULL == (dst = (int *)calloc(sizeof(int), ARRAY_FILL_SIZE * hi)))
+    if (NULL == (dst = (int *)calloc((ARRAY_FILL_SIZE * hi), sizeof(int))))
         TEST_ERROR;
 
     /* Setup */
diff --git a/test/ntypes.c b/test/ntypes.c
index 3fcd40ffb4b..14357087f2a 100644
--- a/test/ntypes.c
+++ b/test/ntypes.c
@@ -335,9 +335,9 @@ test_compound_dtype2(hid_t file)
     TESTING("nested compound datatype");
 
     /* Allocate space for the points & check arrays */
-    if (NULL == (points = malloc(sizeof(s1) * DIM0 * DIM1)))
+    if (NULL == (points = (s1 *)malloc((DIM0 * DIM1) * sizeof(s1))))
         TEST_ERROR;
-    if (NULL == (check = calloc(DIM0 * DIM1, sizeof(s1))))
+    if (NULL == (check = (s1 *)calloc((DIM0 * DIM1), sizeof(s1))))
         TEST_ERROR;
 
     /* Initialize the dataset */
@@ -533,9 +533,9 @@ test_compound_dtype2(hid_t file)
 
     /* Read the dataset back.  Temporary buffer is for special platforms like
      * Cray */
-    if (NULL == (tmp = malloc(DIM0 * DIM1 * H5Tget_size(native_type))))
+    if (NULL == (tmp = malloc((DIM0 * DIM1) * H5Tget_size(native_type))))
         TEST_ERROR;
-    if (NULL == (bkg = calloc(DIM0 * DIM1, sizeof(s1))))
+    if (NULL == (bkg = calloc((DIM0 * DIM1), sizeof(s1))))
         TEST_ERROR;
 
     if (H5Dread(dataset, native_type, H5S_ALL, H5S_ALL, H5P_DEFAULT, tmp) < 0)
@@ -648,9 +648,9 @@ test_compound_dtype(hid_t file)
     TESTING("compound datatype");
 
     /* Allocate space for the points & check arrays */
-    if (NULL == (points = malloc(sizeof(s1) * DIM0 * DIM1)))
+    if (NULL == (points = (s1 *)malloc((DIM0 * DIM1) * sizeof(s1))))
         TEST_ERROR;
-    if (NULL == (check = calloc(DIM0 * DIM1, sizeof(s1))))
+    if (NULL == (check = (s1 *)calloc((DIM0 * DIM1), sizeof(s1))))
         TEST_ERROR;
 
     /* Initialize the dataset */
@@ -752,9 +752,9 @@ test_compound_dtype(hid_t file)
 
     /* Read the dataset back.  Temporary buffer is for special platforms like
      * Cray */
-    if (NULL == (tmp = malloc(DIM0 * DIM1 * H5Tget_size(native_type))))
+    if (NULL == (tmp = malloc((DIM0 * DIM1) * H5Tget_size(native_type))))
         TEST_ERROR;
-    if (NULL == (bkg = calloc(DIM0 * DIM1, sizeof(s1))))
+    if (NULL == (bkg = calloc((DIM0 * DIM1), sizeof(s1))))
         TEST_ERROR;
 
     if (H5Dread(dataset, native_type, H5S_ALL, H5S_ALL, H5P_DEFAULT, tmp) < 0)
@@ -856,9 +856,9 @@ test_compound_dtype3(hid_t file)
     TESTING("compound datatype with array as field");
 
     /* Allocate space for the points & check arrays */
-    if (NULL == (points = malloc(sizeof(s1) * DIM0 * DIM1)))
+    if (NULL == (points = (s1 *)malloc((DIM0 * DIM1) * sizeof(s1))))
         TEST_ERROR;
-    if (NULL == (check = calloc(DIM0 * DIM1, sizeof(s1))))
+    if (NULL == (check = (s1 *)calloc((DIM0 * DIM1), sizeof(s1))))
         TEST_ERROR;
 
     /* Initialize the dataset */
@@ -980,9 +980,9 @@ test_compound_dtype3(hid_t file)
 
     /* Read the dataset back.  Temporary buffer is for special platforms like
      * Cray */
-    if (NULL == (tmp = malloc(DIM0 * DIM1 * H5Tget_size(native_type))))
+    if (NULL == (tmp = malloc((DIM0 * DIM1) * H5Tget_size(native_type))))
         TEST_ERROR;
-    if (NULL == (bkg = calloc(DIM0 * DIM1, sizeof(s1))))
+    if (NULL == (bkg = calloc((DIM0 * DIM1), sizeof(s1))))
         TEST_ERROR;
 
     if (H5Dread(dataset, native_type, H5S_ALL, H5S_ALL, H5P_DEFAULT, tmp) < 0)
@@ -1091,9 +1091,9 @@ test_compound_opaque(hid_t file)
     TESTING("compound datatype with opaque field");
 
     /* Allocate space for the points & check arrays */
-    if (NULL == (points = malloc(sizeof(s1) * DIM0 * DIM1)))
+    if (NULL == (points = (s1 *)malloc((DIM0 * DIM1) * sizeof(s1))))
         TEST_ERROR;
-    if (NULL == (check = calloc(DIM0 * DIM1, sizeof(s1))))
+    if (NULL == (check = (s1 *)calloc((DIM0 * DIM1), sizeof(s1))))
         TEST_ERROR;
 
     /* Initialize the dataset */
@@ -1206,9 +1206,9 @@ test_compound_opaque(hid_t file)
 
     /* Read the dataset back.  Temporary buffer is for special platforms like
      * Cray */
-    if (NULL == (tmp = malloc(DIM0 * DIM1 * H5Tget_size(native_type))))
+    if (NULL == (tmp = malloc((DIM0 * DIM1) * H5Tget_size(native_type))))
         TEST_ERROR;
-    if (NULL == (bkg = calloc(DIM0 * DIM1, sizeof(s1))))
+    if (NULL == (bkg = calloc((DIM0 * DIM1), sizeof(s1))))
         TEST_ERROR;
 
     if (H5Dread(dataset, native_type, H5S_ALL, H5S_ALL, H5P_DEFAULT, tmp) < 0)
@@ -1469,9 +1469,9 @@ test_array_dtype(hid_t file)
     TESTING("array of compound datatype");
 
     /* Allocate space for the points & check arrays */
-    if (NULL == (points = malloc(sizeof(s1) * DIM0 * DIM1 * 5)))
+    if (NULL == (points = (s1 *)malloc((DIM0 * DIM1 * 5) * sizeof(s1))))
         TEST_ERROR;
-    if (NULL == (check = calloc(DIM0 * DIM1 * 5, sizeof(s1))))
+    if (NULL == (check = (s1 *)calloc((DIM0 * DIM1 * 5), sizeof(s1))))
         TEST_ERROR;
 
     /* Initialize the dataset */
@@ -2428,9 +2428,9 @@ test_refer_dtype2(hid_t file)
     TESTING("dataset region reference");
 
     /* Allocate write & read buffers */
-    if (NULL == (dwbuf = malloc(sizeof(uint8_t) * SPACE2_DIM1 * SPACE2_DIM2)))
+    if (NULL == (dwbuf = (uint8_t *)malloc((SPACE2_DIM1 * SPACE2_DIM2) * sizeof(uint8_t))))
         TEST_ERROR;
-    if (NULL == (drbuf = calloc(SPACE2_DIM1 * SPACE2_DIM2, sizeof(uint8_t))))
+    if (NULL == (drbuf = (uint8_t *)calloc((SPACE2_DIM1 * SPACE2_DIM2), sizeof(uint8_t))))
         TEST_ERROR;
 
     /* Create dataspace for datasets */
diff --git a/test/trefer.c b/test/trefer.c
index ac35ea5978f..bc443b7b4be 100644
--- a/test/trefer.c
+++ b/test/trefer.c
@@ -127,7 +127,7 @@ test_reference_params(void)
     wbuf = (H5R_ref_t *)calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
     rbuf = (H5R_ref_t *)calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
     tbuf = (H5R_ref_t *)calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
-    obuf = calloc(SPACE1_DIM1, sizeof(unsigned));
+    obuf = (unsigned *)calloc(SPACE1_DIM1, sizeof(unsigned));
 
     for (i = 0; i < SPACE1_DIM1; i++)
         obuf[i] = i * 3;
@@ -468,10 +468,10 @@ test_reference_obj(void)
     MESSAGE(5, ("Testing Object Reference Functions\n"));
 
     /* Allocate write & read buffers */
-    wbuf = calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
-    rbuf = calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
-    ibuf = calloc(SPACE1_DIM1, sizeof(unsigned));
-    obuf = calloc(SPACE1_DIM1, sizeof(unsigned));
+    wbuf = (H5R_ref_t *)calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
+    rbuf = (H5R_ref_t *)calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
+    ibuf = (unsigned *)calloc(SPACE1_DIM1, sizeof(unsigned));
+    obuf = (unsigned *)calloc(SPACE1_DIM1, sizeof(unsigned));
 
     for (i = 0; i < SPACE1_DIM1; i++)
         obuf[i] = i * 3;
@@ -571,7 +571,7 @@ test_reference_obj(void)
     VERIFY(obj_type, H5O_TYPE_NAMED_DATATYPE, "H5Rget_obj_type3");
 
     /* Check copying a reference */
-    wbuf_cp = calloc(1, sizeof(H5R_ref_t));
+    wbuf_cp = (H5R_ref_t *)calloc(1, sizeof(H5R_ref_t));
     ret     = H5Rcopy(&wbuf[0], &wbuf_cp[0]);
     CHECK(ret, FAIL, "H5Rcopy");
 
@@ -838,9 +838,9 @@ test_reference_vlen_obj(void)
     MESSAGE(5, ("Testing Object Reference Functions within VLEN type\n"));
 
     /* Allocate write & read buffers */
-    wbuf = calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
-    ibuf = calloc(SPACE1_DIM1, sizeof(unsigned));
-    obuf = calloc(SPACE1_DIM1, sizeof(unsigned));
+    wbuf = (H5R_ref_t *)calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
+    ibuf = (unsigned *)calloc(SPACE1_DIM1, sizeof(unsigned));
+    obuf = (unsigned *)calloc(SPACE1_DIM1, sizeof(unsigned));
 
     for (i = 0; i < SPACE1_DIM1; i++)
         obuf[i] = i * 3;
@@ -1102,8 +1102,8 @@ test_reference_cmpnd_obj(void)
     MESSAGE(5, ("Testing Object Reference Functions within compound type\n"));
 
     /* Allocate write & read buffers */
-    ibuf = calloc(SPACE1_DIM1, sizeof(unsigned));
-    obuf = calloc(SPACE1_DIM1, sizeof(unsigned));
+    ibuf = (unsigned *)calloc(SPACE1_DIM1, sizeof(unsigned));
+    obuf = (unsigned *)calloc(SPACE1_DIM1, sizeof(unsigned));
 
     for (i = 0; i < SPACE1_DIM1; i++)
         obuf[i] = i * 3;
@@ -1411,10 +1411,10 @@ test_reference_region(H5F_libver_t libver_low, H5F_libver_t libver_high)
     MESSAGE(5, ("Testing Dataset Region Reference Functions\n"));
 
     /* Allocate write & read buffers */
-    wbuf  = calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
-    rbuf  = calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
-    dwbuf = (uint8_t *)calloc((size_t)(SPACE2_DIM1 * SPACE2_DIM2), sizeof(uint8_t));
-    drbuf = (uint8_t *)calloc((size_t)(SPACE2_DIM1 * SPACE2_DIM2), sizeof(uint8_t));
+    wbuf  = (H5R_ref_t *)calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
+    rbuf  = (H5R_ref_t *)calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
+    dwbuf = (uint8_t *)calloc((SPACE2_DIM1 * SPACE2_DIM2), sizeof(uint8_t));
+    drbuf = (uint8_t *)calloc((SPACE2_DIM1 * SPACE2_DIM2), sizeof(uint8_t));
 
     for (tu8 = dwbuf, i = 0; i < (SPACE2_DIM1 * SPACE2_DIM2); i++)
         *tu8++ = (uint8_t)(i * 3);
@@ -1867,10 +1867,10 @@ test_reference_region_1D(H5F_libver_t libver_low, H5F_libver_t libver_high)
     MESSAGE(5, ("Testing 1-D Dataset Region Reference Functions\n"));
 
     /* Allocate write & read buffers */
-    wbuf  = calloc((size_t)SPACE1_DIM1, sizeof(H5R_ref_t));
-    rbuf  = calloc((size_t)SPACE1_DIM1, sizeof(H5R_ref_t));
-    dwbuf = (uint8_t *)calloc((size_t)SPACE3_DIM1, sizeof(uint8_t));
-    drbuf = (uint8_t *)calloc((size_t)SPACE3_DIM1, sizeof(uint8_t));
+    wbuf  = (H5R_ref_t *)calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
+    rbuf  = (H5R_ref_t *)calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
+    dwbuf = (uint8_t *)calloc(SPACE3_DIM1, sizeof(uint8_t));
+    drbuf = (uint8_t *)calloc(SPACE3_DIM1, sizeof(uint8_t));
 
     for (tu8 = dwbuf, i = 0; i < SPACE3_DIM1; i++)
         *tu8++ = (uint8_t)(i * 3);
@@ -3125,10 +3125,10 @@ test_reference_compat_conv(void)
     }
 
     /* Allocate write & read buffers */
-    wbuf_obj = calloc(SPACE1_DIM1, sizeof(hobj_ref_t));
-    rbuf_obj = calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
-    wbuf_reg = calloc(SPACE1_DIM1, sizeof(hdset_reg_ref_t));
-    rbuf_reg = calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
+    wbuf_obj = (hobj_ref_t *)calloc(SPACE1_DIM1, sizeof(hobj_ref_t));
+    rbuf_obj = (H5R_ref_t *)calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
+    wbuf_reg = (hdset_reg_ref_t *)calloc(SPACE1_DIM1, sizeof(hdset_reg_ref_t));
+    rbuf_reg = (H5R_ref_t *)calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
 
     /* Create dataspace for datasets */
     sid1 = H5Screate_simple(SPACE1_RANK, dims1, NULL);
@@ -3434,17 +3434,17 @@ test_reference_perf(void)
     MESSAGE(5, ("Testing Object Reference Performance\n"));
 
     /* Allocate write & read buffers */
-    wbuf            = calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
-    obuf            = calloc(SPACE1_DIM1, sizeof(unsigned));
-    ibuf            = calloc(SPACE1_DIM1, sizeof(unsigned));
-    wbuf_deprec     = calloc(SPACE1_DIM1, sizeof(hobj_ref_t));
-    rbuf            = calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
-    rbuf_deprec     = calloc(SPACE1_DIM1, sizeof(hobj_ref_t));
-    tbuf            = calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
-    wbuf_reg        = calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
-    rbuf_reg        = calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
-    wbuf_reg_deprec = calloc(SPACE1_DIM1, sizeof(hdset_reg_ref_t));
-    rbuf_reg_deprec = calloc(SPACE1_DIM1, sizeof(hdset_reg_ref_t));
+    wbuf            = (H5R_ref_t *)calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
+    obuf            = (unsigned *)calloc(SPACE1_DIM1, sizeof(unsigned));
+    ibuf            = (unsigned *)calloc(SPACE1_DIM1, sizeof(unsigned));
+    wbuf_deprec     = (hobj_ref_t *)calloc(SPACE1_DIM1, sizeof(hobj_ref_t));
+    rbuf            = (H5R_ref_t *)calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
+    rbuf_deprec     = (hobj_ref_t *)calloc(SPACE1_DIM1, sizeof(hobj_ref_t));
+    tbuf            = (H5R_ref_t *)calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
+    wbuf_reg        = (H5R_ref_t *)calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
+    rbuf_reg        = (H5R_ref_t *)calloc(SPACE1_DIM1, sizeof(H5R_ref_t));
+    wbuf_reg_deprec = (hdset_reg_ref_t *)calloc(SPACE1_DIM1, sizeof(hdset_reg_ref_t));
+    rbuf_reg_deprec = (hdset_reg_ref_t *)calloc(SPACE1_DIM1, sizeof(hdset_reg_ref_t));
 
     for (i = 0; i < SPACE1_DIM1; i++)
         obuf[i] = i * 3;
diff --git a/test/trefer_deprec.c b/test/trefer_deprec.c
index 3f932f53b93..d06f5e39ef1 100644
--- a/test/trefer_deprec.c
+++ b/test/trefer_deprec.c
@@ -623,10 +623,10 @@ test_reference_region(H5F_libver_t libver_low, H5F_libver_t libver_high)
     MESSAGE(5, ("Testing Dataset Region Reference Functions\n"));
 
     /* Allocate write & read buffers */
-    wbuf  = calloc((size_t)SPACE1_DIM1, sizeof(hdset_reg_ref_t));
-    rbuf  = malloc(sizeof(hdset_reg_ref_t) * SPACE1_DIM1);
-    dwbuf = malloc(sizeof(uint8_t) * SPACE2_DIM1 * SPACE2_DIM2);
-    drbuf = calloc((size_t)(SPACE2_DIM1 * SPACE2_DIM2), sizeof(uint8_t));
+    wbuf  = (hdset_reg_ref_t *)calloc(SPACE1_DIM1, sizeof(hdset_reg_ref_t));
+    rbuf  = (hdset_reg_ref_t *)malloc(SPACE1_DIM1 * sizeof(hdset_reg_ref_t));
+    dwbuf = (uint8_t *)malloc((SPACE2_DIM1 * SPACE2_DIM2) * sizeof(uint8_t));
+    drbuf = (uint8_t *)calloc((SPACE2_DIM1 * SPACE2_DIM2), sizeof(uint8_t));
 
     /* Create file access property list */
     fapl = H5Pcreate(H5P_FILE_ACCESS);
@@ -1064,10 +1064,10 @@ test_reference_region_1D(H5F_libver_t libver_low, H5F_libver_t libver_high)
     MESSAGE(5, ("Testing 1-D Dataset Region Reference Functions\n"));
 
     /* Allocate write & read buffers */
-    wbuf  = calloc((size_t)SPACE1_DIM1, sizeof(hdset_reg_ref_t));
-    rbuf  = malloc(sizeof(hdset_reg_ref_t) * SPACE1_DIM1);
-    dwbuf = malloc(sizeof(uint8_t) * SPACE3_DIM1);
-    drbuf = calloc((size_t)SPACE3_DIM1, sizeof(uint8_t));
+    wbuf  = (hdset_reg_ref_t *)calloc(SPACE1_DIM1, sizeof(hdset_reg_ref_t));
+    rbuf  = (hdset_reg_ref_t *)malloc(SPACE1_DIM1 * sizeof(hdset_reg_ref_t));
+    dwbuf = (uint8_t *)malloc(SPACE3_DIM1 * sizeof(uint8_t));
+    drbuf = (uint8_t *)calloc(SPACE3_DIM1, sizeof(uint8_t));
 
     /* Create the file access property list */
     fapl = H5Pcreate(H5P_FILE_ACCESS);
@@ -1636,10 +1636,10 @@ test_reference_compat(void)
     MESSAGE(5, ("Testing Deprecated Object Reference Functions\n"));
 
     /* Allocate write & read buffers */
-    wbuf_obj = calloc(SPACE1_DIM1, sizeof(hobj_ref_t));
-    rbuf_obj = malloc(sizeof(hobj_ref_t) * SPACE1_DIM1);
-    wbuf_reg = calloc(SPACE1_DIM1, sizeof(hdset_reg_ref_t));
-    rbuf_reg = malloc(sizeof(hdset_reg_ref_t) * SPACE1_DIM1);
+    wbuf_obj = (hobj_ref_t *)calloc(SPACE1_DIM1, sizeof(hobj_ref_t));
+    rbuf_obj = (hobj_ref_t *)malloc(SPACE1_DIM1 * sizeof(hobj_ref_t));
+    wbuf_reg = (hdset_reg_ref_t *)calloc(SPACE1_DIM1, sizeof(hdset_reg_ref_t));
+    rbuf_reg = (hdset_reg_ref_t *)malloc(SPACE1_DIM1 * sizeof(hdset_reg_ref_t));
 
     /* Create file */
     fid1 = H5Fcreate(FILE1, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
diff --git a/test/tselect.c b/test/tselect.c
index 6f9bc6f1426..21c3648d587 100644
--- a/test/tselect.c
+++ b/test/tselect.c
@@ -247,9 +247,9 @@ test_select_hyper(hid_t xfer_plist)
     MESSAGE(5, ("Testing Hyperslab Selection Functions\n"));
 
     /* Allocate write & read buffers */
-    wbuf = (uint8_t *)malloc(sizeof(uint8_t) * SPACE2_DIM1 * SPACE2_DIM2);
+    wbuf = (uint8_t *)malloc((SPACE2_DIM1 * SPACE2_DIM2) * sizeof(uint8_t));
     CHECK_PTR(wbuf, "malloc");
-    rbuf = (uint8_t *)calloc((size_t)(SPACE3_DIM1 * SPACE3_DIM2), sizeof(uint8_t));
+    rbuf = (uint8_t *)calloc((SPACE3_DIM1 * SPACE3_DIM2), sizeof(uint8_t));
     CHECK_PTR(rbuf, "calloc");
 
     /* Initialize write buffer */
@@ -501,9 +501,9 @@ test_select_point(hid_t xfer_plist)
     MESSAGE(5, ("Testing Element Selection Functions\n"));
 
     /* Allocate write & read buffers */
-    wbuf = (uint8_t *)malloc(sizeof(uint8_t) * SPACE2_DIM1 * SPACE2_DIM2);
+    wbuf = (uint8_t *)malloc((SPACE2_DIM1 * SPACE2_DIM2) * sizeof(uint8_t));
     CHECK_PTR(wbuf, "malloc");
-    rbuf = (uint8_t *)calloc((size_t)(SPACE3_DIM1 * SPACE3_DIM2), sizeof(uint8_t));
+    rbuf = (uint8_t *)calloc((SPACE3_DIM1 * SPACE3_DIM2), sizeof(uint8_t));
     CHECK_PTR(rbuf, "calloc");
 
     /* Initialize write buffer */
@@ -863,9 +863,9 @@ test_select_all(hid_t xfer_plist)
     MESSAGE(5, ("Testing 'All' Selection Functions\n"));
 
     /* Allocate write & read buffers */
-    wbuf = (uint8_t *)malloc(sizeof(uint8_t) * SPACE4_DIM1 * SPACE4_DIM2 * SPACE4_DIM3);
+    wbuf = (uint8_t *)malloc((SPACE4_DIM1 * SPACE4_DIM2 * SPACE4_DIM3) * sizeof(uint8_t));
     CHECK_PTR(wbuf, "malloc");
-    rbuf = (uint8_t *)calloc((size_t)(SPACE4_DIM1 * SPACE4_DIM2 * SPACE4_DIM3), sizeof(uint8_t));
+    rbuf = (uint8_t *)calloc((SPACE4_DIM1 * SPACE4_DIM2 * SPACE4_DIM3), sizeof(uint8_t));
     CHECK_PTR(rbuf, "calloc");
 
     /* Initialize write buffer */
@@ -950,9 +950,9 @@ test_select_all_hyper(hid_t xfer_plist)
     MESSAGE(5, ("Testing 'All' Selection Functions\n"));
 
     /* Allocate write & read buffers */
-    wbuf = (uint8_t *)malloc(sizeof(uint8_t) * SPACE2_DIM1 * SPACE2_DIM2);
+    wbuf = (uint8_t *)malloc((SPACE2_DIM1 * SPACE2_DIM2) * sizeof(uint8_t));
     CHECK_PTR(wbuf, "malloc");
-    rbuf = (uint8_t *)calloc((size_t)(SPACE3_DIM1 * SPACE3_DIM2), sizeof(uint8_t));
+    rbuf = (uint8_t *)calloc((SPACE3_DIM1 * SPACE3_DIM2), sizeof(uint8_t));
     CHECK_PTR(rbuf, "calloc");
 
     /* Initialize write buffer */
@@ -1104,9 +1104,9 @@ test_select_combo(void)
     MESSAGE(5, ("Testing Combination of Hyperslab & Element Selection Functions\n"));
 
     /* Allocate write & read buffers */
-    wbuf = (uint8_t *)malloc(sizeof(uint8_t) * SPACE2_DIM1 * SPACE2_DIM2);
+    wbuf = (uint8_t *)malloc((SPACE2_DIM1 * SPACE2_DIM2) * sizeof(uint8_t));
     CHECK_PTR(wbuf, "malloc");
-    rbuf = (uint8_t *)calloc((size_t)(SPACE3_DIM1 * SPACE3_DIM2), sizeof(uint8_t));
+    rbuf = (uint8_t *)calloc((SPACE3_DIM1 * SPACE3_DIM2), sizeof(uint8_t));
     CHECK_PTR(rbuf, "calloc");
 
     /* Initialize write buffer */
@@ -1299,9 +1299,9 @@ test_select_hyper_stride(hid_t xfer_plist)
     MESSAGE(5, ("Testing Hyperslabs with Strides Functionality\n"));
 
     /* Allocate write & read buffers */
-    wbuf = (uint16_t *)malloc(sizeof(uint16_t) * SPACE2_DIM1 * SPACE2_DIM2);
+    wbuf = (uint16_t *)malloc((SPACE2_DIM1 * SPACE2_DIM2) * sizeof(uint16_t));
     CHECK_PTR(wbuf, "malloc");
-    rbuf = (uint16_t *)calloc((size_t)(SPACE3_DIM1 * SPACE3_DIM2), sizeof(uint16_t));
+    rbuf = (uint16_t *)calloc((SPACE3_DIM1 * SPACE3_DIM2), sizeof(uint16_t));
     CHECK_PTR(rbuf, "calloc");
 
     /* Initialize write buffer */
@@ -1445,9 +1445,9 @@ test_select_hyper_contig(hid_t dset_type, hid_t xfer_plist)
     MESSAGE(5, ("Testing Contiguous Hyperslabs Functionality\n"));
 
     /* Allocate write & read buffers */
-    wbuf = (uint16_t *)malloc(sizeof(uint16_t) * SPACE2_DIM1 * SPACE2_DIM2);
+    wbuf = (uint16_t *)malloc((SPACE2_DIM1 * SPACE2_DIM2) * sizeof(uint16_t));
     CHECK_PTR(wbuf, "malloc");
-    rbuf = (uint16_t *)calloc((size_t)(SPACE2_DIM1 * SPACE2_DIM2), sizeof(uint16_t));
+    rbuf = (uint16_t *)calloc((SPACE2_DIM1 * SPACE2_DIM2), sizeof(uint16_t));
     CHECK_PTR(rbuf, "calloc");
 
     /* Initialize write buffer */
@@ -1585,10 +1585,9 @@ test_select_hyper_contig2(hid_t dset_type, hid_t xfer_plist)
     MESSAGE(5, ("Testing More Contiguous Hyperslabs Functionality\n"));
 
     /* Allocate write & read buffers */
-    wbuf = (uint16_t *)malloc(sizeof(uint16_t) * SPACE8_DIM1 * SPACE8_DIM2 * SPACE8_DIM3 * SPACE8_DIM4);
+    wbuf = (uint16_t *)malloc((SPACE8_DIM1 * SPACE8_DIM2 * SPACE8_DIM3 * SPACE8_DIM4) * sizeof(uint16_t));
     CHECK_PTR(wbuf, "malloc");
-    rbuf =
-        (uint16_t *)calloc((size_t)(SPACE8_DIM1 * SPACE8_DIM2 * SPACE8_DIM3 * SPACE8_DIM4), sizeof(uint16_t));
+    rbuf = (uint16_t *)calloc((SPACE8_DIM1 * SPACE8_DIM2 * SPACE8_DIM3 * SPACE8_DIM4), sizeof(uint16_t));
     CHECK_PTR(rbuf, "calloc");
 
     /* Initialize write buffer */
@@ -1731,10 +1730,9 @@ test_select_hyper_contig3(hid_t dset_type, hid_t xfer_plist)
     MESSAGE(5, ("Testing Yet More Contiguous Hyperslabs Functionality\n"));
 
     /* Allocate write & read buffers */
-    wbuf = (uint16_t *)malloc(sizeof(uint16_t) * SPACE8_DIM1 * SPACE8_DIM2 * SPACE8_DIM3 * SPACE8_DIM4);
+    wbuf = (uint16_t *)malloc((SPACE8_DIM1 * SPACE8_DIM2 * SPACE8_DIM3 * SPACE8_DIM4) * sizeof(uint16_t));
     CHECK_PTR(wbuf, "malloc");
-    rbuf =
-        (uint16_t *)calloc((size_t)(SPACE8_DIM1 * SPACE8_DIM2 * SPACE8_DIM3 * SPACE8_DIM4), sizeof(uint16_t));
+    rbuf = (uint16_t *)calloc((SPACE8_DIM1 * SPACE8_DIM2 * SPACE8_DIM3 * SPACE8_DIM4), sizeof(uint16_t));
     CHECK_PTR(rbuf, "calloc");
 
     /* Initialize write buffer */
@@ -3679,11 +3677,11 @@ test_select_hyper_copy(void)
     MESSAGE(5, ("Testing Hyperslabs with Strides Functionality\n"));
 
     /* Allocate write & read buffers */
-    wbuf = (uint16_t *)malloc(sizeof(uint16_t) * SPACE2_DIM1 * SPACE2_DIM2);
+    wbuf = (uint16_t *)malloc((SPACE2_DIM1 * SPACE2_DIM2) * sizeof(uint16_t));
     CHECK_PTR(wbuf, "malloc");
-    rbuf = (uint16_t *)calloc((size_t)(SPACE3_DIM1 * SPACE3_DIM2), sizeof(uint16_t));
+    rbuf = (uint16_t *)calloc((SPACE3_DIM1 * SPACE3_DIM2), sizeof(uint16_t));
     CHECK_PTR(rbuf, "calloc");
-    rbuf2 = (uint16_t *)calloc((size_t)(SPACE3_DIM1 * SPACE3_DIM2), sizeof(uint16_t));
+    rbuf2 = (uint16_t *)calloc((SPACE3_DIM1 * SPACE3_DIM2), sizeof(uint16_t));
     CHECK_PTR(rbuf2, "calloc");
 
     /* Initialize write buffer */
@@ -3850,11 +3848,11 @@ test_select_point_copy(void)
     MESSAGE(5, ("Testing Hyperslabs with Strides Functionality\n"));
 
     /* Allocate write & read buffers */
-    wbuf = (uint16_t *)malloc(sizeof(uint16_t) * SPACE2_DIM1 * SPACE2_DIM2);
+    wbuf = (uint16_t *)malloc((SPACE2_DIM1 * SPACE2_DIM2) * sizeof(uint16_t));
     CHECK_PTR(wbuf, "malloc");
-    rbuf = (uint16_t *)calloc((size_t)(SPACE3_DIM1 * SPACE3_DIM2), sizeof(uint16_t));
+    rbuf = (uint16_t *)calloc((SPACE3_DIM1 * SPACE3_DIM2), sizeof(uint16_t));
     CHECK_PTR(rbuf, "calloc");
-    rbuf2 = (uint16_t *)calloc((size_t)(SPACE3_DIM1 * SPACE3_DIM2), sizeof(uint16_t));
+    rbuf2 = (uint16_t *)calloc((SPACE3_DIM1 * SPACE3_DIM2), sizeof(uint16_t));
     CHECK_PTR(rbuf2, "calloc");
 
     /* Initialize write buffer */
@@ -4068,9 +4066,9 @@ test_select_hyper_offset(void)
     MESSAGE(5, ("Testing Hyperslab Selection Functions with Offsets\n"));
 
     /* Allocate write & read buffers */
-    wbuf = (uint8_t *)malloc(sizeof(uint8_t) * SPACE2_DIM1 * SPACE2_DIM2);
+    wbuf = (uint8_t *)malloc((SPACE2_DIM1 * SPACE2_DIM2) * sizeof(uint8_t));
     CHECK_PTR(wbuf, "malloc");
-    rbuf = (uint8_t *)calloc((size_t)(SPACE3_DIM1 * SPACE3_DIM2), sizeof(uint8_t));
+    rbuf = (uint8_t *)calloc((SPACE3_DIM1 * SPACE3_DIM2), sizeof(uint8_t));
     CHECK_PTR(rbuf, "calloc");
 
     /* Initialize write buffer */
@@ -4276,9 +4274,9 @@ test_select_hyper_offset2(void)
     MESSAGE(5, ("Testing More Hyperslab Selection Functions with Offsets\n"));
 
     /* Allocate write & read buffers */
-    wbuf = (uint8_t *)malloc(sizeof(uint8_t) * SPACE7_DIM1 * SPACE7_DIM2);
+    wbuf = (uint8_t *)malloc((SPACE7_DIM1 * SPACE7_DIM2) * sizeof(uint8_t));
     CHECK_PTR(wbuf, "malloc");
-    rbuf = (uint8_t *)calloc((size_t)(SPACE7_DIM1 * SPACE7_DIM2), sizeof(uint8_t));
+    rbuf = (uint8_t *)calloc((SPACE7_DIM1 * SPACE7_DIM2), sizeof(uint8_t));
     CHECK_PTR(rbuf, "calloc");
 
     /* Initialize write buffer */
@@ -4406,9 +4404,9 @@ test_select_point_offset(void)
     MESSAGE(5, ("Testing Element Selection Functions\n"));
 
     /* Allocate write & read buffers */
-    wbuf = (uint8_t *)malloc(sizeof(uint8_t) * SPACE2_DIM1 * SPACE2_DIM2);
+    wbuf = (uint8_t *)malloc((SPACE2_DIM1 * SPACE2_DIM2) * sizeof(uint8_t));
     CHECK_PTR(wbuf, "malloc");
-    rbuf = (uint8_t *)calloc((size_t)(SPACE3_DIM1 * SPACE3_DIM2), sizeof(uint8_t));
+    rbuf = (uint8_t *)calloc((SPACE3_DIM1 * SPACE3_DIM2), sizeof(uint8_t));
     CHECK_PTR(rbuf, "calloc");
 
     /* Initialize write buffer */
@@ -4633,9 +4631,9 @@ test_select_hyper_union(void)
     MESSAGE(5, ("Testing Hyperslab Selection Functions with unions of hyperslabs\n"));
 
     /* Allocate write & read buffers */
-    wbuf = (uint8_t *)malloc(sizeof(uint8_t) * SPACE2_DIM1 * SPACE2_DIM2);
+    wbuf = (uint8_t *)malloc((SPACE2_DIM1 * SPACE2_DIM2) * sizeof(uint8_t));
     CHECK_PTR(wbuf, "malloc");
-    rbuf = (uint8_t *)calloc((size_t)(SPACE3_DIM1 * SPACE3_DIM2), sizeof(uint8_t));
+    rbuf = (uint8_t *)calloc((SPACE3_DIM1 * SPACE3_DIM2), sizeof(uint8_t));
     CHECK_PTR(rbuf, "calloc");
 
     /* Initialize write buffer */
@@ -5411,9 +5409,9 @@ test_select_hyper_union_3d(void)
     MESSAGE(5, ("Testing Hyperslab Selection Functions with unions of 3-D hyperslabs\n"));
 
     /* Allocate write & read buffers */
-    wbuf = (uint8_t *)malloc(sizeof(uint8_t) * SPACE4_DIM1 * SPACE4_DIM2 * SPACE4_DIM3);
+    wbuf = (uint8_t *)malloc((SPACE4_DIM1 * SPACE4_DIM2 * SPACE4_DIM3) * sizeof(uint8_t));
     CHECK_PTR(wbuf, "malloc");
-    rbuf = (uint8_t *)calloc(SPACE3_DIM1 * SPACE3_DIM2, sizeof(uint8_t));
+    rbuf = (uint8_t *)calloc((SPACE3_DIM1 * SPACE3_DIM2), sizeof(uint8_t));
     CHECK_PTR(rbuf, "calloc");
 
     /* Initialize write buffer */
@@ -5735,9 +5733,9 @@ test_select_hyper_and_2d(void)
     MESSAGE(5, ("Testing Hyperslab Selection Functions with intersection of 2-D hyperslabs\n"));
 
     /* Allocate write & read buffers */
-    wbuf = (uint8_t *)malloc(sizeof(uint8_t) * SPACE2_DIM1 * SPACE2_DIM2);
+    wbuf = (uint8_t *)malloc((SPACE2_DIM1 * SPACE2_DIM2) * sizeof(uint8_t));
     CHECK_PTR(wbuf, "malloc");
-    rbuf = (uint8_t *)calloc((size_t)(SPACE2_DIM1 * SPACE2_DIM2), sizeof(uint8_t));
+    rbuf = (uint8_t *)calloc((SPACE2_DIM1 * SPACE2_DIM2), sizeof(uint8_t));
     CHECK_PTR(rbuf, "calloc");
 
     /* Initialize write buffer */
@@ -5874,9 +5872,9 @@ test_select_hyper_xor_2d(void)
     MESSAGE(5, ("Testing Hyperslab Selection Functions with XOR of 2-D hyperslabs\n"));
 
     /* Allocate write & read buffers */
-    wbuf = (uint8_t *)malloc(sizeof(uint8_t) * SPACE2_DIM1 * SPACE2_DIM2);
+    wbuf = (uint8_t *)malloc((SPACE2_DIM1 * SPACE2_DIM2) * sizeof(uint8_t));
     CHECK_PTR(wbuf, "malloc");
-    rbuf = (uint8_t *)calloc((size_t)(SPACE2_DIM1 * SPACE2_DIM2), sizeof(uint8_t));
+    rbuf = (uint8_t *)calloc((SPACE2_DIM1 * SPACE2_DIM2), sizeof(uint8_t));
     CHECK_PTR(rbuf, "calloc");
 
     /* Initialize write buffer */
@@ -6015,9 +6013,9 @@ test_select_hyper_notb_2d(void)
     MESSAGE(5, ("Testing Hyperslab Selection Functions with NOTB of 2-D hyperslabs\n"));
 
     /* Allocate write & read buffers */
-    wbuf = (uint8_t *)malloc(sizeof(uint8_t) * SPACE2_DIM1 * SPACE2_DIM2);
+    wbuf = (uint8_t *)malloc((SPACE2_DIM1 * SPACE2_DIM2) * sizeof(uint8_t));
     CHECK_PTR(wbuf, "malloc");
-    rbuf = (uint8_t *)calloc((size_t)(SPACE2_DIM1 * SPACE2_DIM2), sizeof(uint8_t));
+    rbuf = (uint8_t *)calloc((SPACE2_DIM1 * SPACE2_DIM2), sizeof(uint8_t));
     CHECK_PTR(rbuf, "calloc");
 
     /* Initialize write buffer */
@@ -6154,9 +6152,9 @@ test_select_hyper_nota_2d(void)
     MESSAGE(5, ("Testing Hyperslab Selection Functions with NOTA of 2-D hyperslabs\n"));
 
     /* Allocate write & read buffers */
-    wbuf = (uint8_t *)malloc(sizeof(uint8_t) * SPACE2_DIM1 * SPACE2_DIM2);
+    wbuf = (uint8_t *)malloc((SPACE2_DIM1 * SPACE2_DIM2) * sizeof(uint8_t));
     CHECK_PTR(wbuf, "malloc");
-    rbuf = (uint8_t *)calloc((size_t)(SPACE2_DIM1 * SPACE2_DIM2), sizeof(uint8_t));
+    rbuf = (uint8_t *)calloc((SPACE2_DIM1 * SPACE2_DIM2), sizeof(uint8_t));
     CHECK_PTR(rbuf, "calloc");
 
     /* Initialize write buffer */
@@ -6324,10 +6322,9 @@ test_select_hyper_union_random_5d(hid_t read_plist)
     MESSAGE(5, ("Testing Hyperslab Selection Functions with random unions of 5-D hyperslabs\n"));
 
     /* Allocate write & read buffers */
-    wbuf = (int *)malloc(sizeof(int) * SPACE5_DIM1 * SPACE5_DIM2 * SPACE5_DIM3 * SPACE5_DIM4 * SPACE5_DIM5);
+    wbuf = (int *)malloc((SPACE5_DIM1 * SPACE5_DIM2 * SPACE5_DIM3 * SPACE5_DIM4 * SPACE5_DIM5) * sizeof(int));
     CHECK_PTR(wbuf, "malloc");
-    rbuf = (int *)calloc((size_t)(SPACE5_DIM1 * SPACE5_DIM2 * SPACE5_DIM3 * SPACE5_DIM4 * SPACE5_DIM5),
-                         sizeof(int));
+    rbuf = (int *)calloc((SPACE5_DIM1 * SPACE5_DIM2 * SPACE5_DIM3 * SPACE5_DIM4 * SPACE5_DIM5), sizeof(int));
     CHECK_PTR(rbuf, "calloc");
 
     /* Initialize write buffer */
@@ -7995,9 +7992,9 @@ test_select_none(void)
     MESSAGE(5, ("Testing I/O on 0-sized Selections\n"));
 
     /* Allocate write & read buffers */
-    wbuf = (uint8_t *)malloc(sizeof(uint8_t) * SPACE7_DIM1 * SPACE7_DIM2);
+    wbuf = (uint8_t *)malloc((SPACE7_DIM1 * SPACE7_DIM2) * sizeof(uint8_t));
     CHECK_PTR(wbuf, "malloc");
-    rbuf = (uint8_t *)calloc(SPACE7_DIM1 * SPACE7_DIM2, sizeof(uint8_t));
+    rbuf = (uint8_t *)calloc((SPACE7_DIM1 * SPACE7_DIM2), sizeof(uint8_t));
     CHECK_PTR(rbuf, "calloc");
 
     /* Initialize write buffer */
@@ -13579,7 +13576,7 @@ test_select_hyper_chunk_offset(void)
     MESSAGE(6, ("Testing hyperslab selections using offsets in chunked datasets\n"));
 
     /* Allocate buffers */
-    wbuf = (int *)malloc(sizeof(int) * SPACE10_DIM1);
+    wbuf = (int *)malloc(SPACE10_DIM1 * sizeof(int));
     CHECK_PTR(wbuf, "malloc");
     rbuf = (int *)calloc(SPACE10_DIM1, sizeof(int));
     CHECK_PTR(rbuf, "calloc");
diff --git a/tools/src/h5repack/h5repack_refs.c b/tools/src/h5repack/h5repack_refs.c
index bbdc135ffda..0c281b006e8 100644
--- a/tools/src/h5repack/h5repack_refs.c
+++ b/tools/src/h5repack/h5repack_refs.c
@@ -234,7 +234,7 @@ do_copy_refobjs(hid_t fidin, hid_t fidout, trav_table_t *travt, pack_opt_t *opti
                          *-------------------------------------------------------------------------
                          */
                         if (nelmts) {
-                            buf = (hdset_reg_ref_t *)malloc((unsigned)(nelmts * msize));
+                            buf = (hdset_reg_ref_t *)malloc((size_t)(nelmts * msize));
                             if (buf == NULL) {
                                 printf("cannot read into memory\n");
                                 H5TOOLS_GOTO_ERROR((-1), "malloc failed");
@@ -246,8 +246,7 @@ do_copy_refobjs(hid_t fidin, hid_t fidout, trav_table_t *travt, pack_opt_t *opti
                              * create output
                              *-------------------------------------------------------------------------
                              */
-                            refbuf = (hdset_reg_ref_t *)calloc(sizeof(hdset_reg_ref_t),
-                                                               (size_t)nelmts); /*init to zero */
+                            refbuf = (hdset_reg_ref_t *)calloc((size_t)nelmts, sizeof(hdset_reg_ref_t));
                             if (refbuf == NULL) {
                                 printf("cannot allocate memory\n");
                                 H5TOOLS_GOTO_ERROR((-1), "calloc failed");
diff --git a/tools/test/h5dump/h5dumpgentest.c b/tools/test/h5dump/h5dumpgentest.c
index 5c13d614844..bac3d9fab1d 100644
--- a/tools/test/h5dump/h5dumpgentest.c
+++ b/tools/test/h5dump/h5dumpgentest.c
@@ -2254,10 +2254,10 @@ gent_datareg(void)
     int      i;                                           /* counting variables */
 
     /* Allocate write & read buffers */
-    wbuf  = (hdset_reg_ref_t *)calloc(sizeof(hdset_reg_ref_t), SPACE1_DIM1);
-    rbuf  = (hdset_reg_ref_t *)malloc(sizeof(hdset_reg_ref_t) * SPACE1_DIM1);
-    dwbuf = (uint8_t *)malloc(sizeof(uint8_t) * SPACE2_DIM1 * SPACE2_DIM2);
-    drbuf = (uint8_t *)calloc(sizeof(uint8_t), SPACE2_DIM1 * SPACE2_DIM2);
+    wbuf  = (hdset_reg_ref_t *)calloc(SPACE1_DIM1, sizeof(hdset_reg_ref_t));
+    rbuf  = (hdset_reg_ref_t *)malloc(SPACE1_DIM1 * sizeof(hdset_reg_ref_t));
+    dwbuf = (uint8_t *)malloc((SPACE2_DIM1 * SPACE2_DIM2) * sizeof(uint8_t));
+    drbuf = (uint8_t *)calloc((SPACE2_DIM1 * SPACE2_DIM2), sizeof(uint8_t));
 
     /* Create file */
     fid1 = H5Fcreate(FILE17, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
diff --git a/tools/test/h5repack/h5repacktst.c b/tools/test/h5repack/h5repacktst.c
index e3c34fe82ab..784ebc78651 100644
--- a/tools/test/h5repack/h5repacktst.c
+++ b/tools/test/h5repack/h5repacktst.c
@@ -4682,8 +4682,8 @@ make_dset_reg_ref(hid_t loc_id)
     int              retval = -1;         /* return value */
 
     /* Allocate write & read buffers */
-    wbuf  = (hdset_reg_ref_t *)calloc(sizeof(hdset_reg_ref_t), (size_t)SPACE1_DIM1);
-    dwbuf = (int *)malloc(sizeof(int) * SPACE2_DIM1 * SPACE2_DIM2);
+    wbuf  = (hdset_reg_ref_t *)calloc(SPACE1_DIM1, sizeof(hdset_reg_ref_t));
+    dwbuf = (int *)malloc((SPACE2_DIM1 * SPACE2_DIM2) * sizeof(int));
 
     /* Create dataspace for datasets */
     if ((sid2 = H5Screate_simple(SPACE2_RANK, dims2, NULL)) < 0)