diff --git a/lib/common/bits.h b/lib/common/bits.h
index f452f0889..910ffa388 100644
--- a/lib/common/bits.h
+++ b/lib/common/bits.h
@@ -21,7 +21,7 @@ MEM_STATIC unsigned ZSTD_countTrailingZeros32_fallback(U32 val)
                                                 30, 22, 20, 15, 25, 17, 4, 8,
                                                 31, 27, 13, 23, 21, 19, 16, 7,
                                                 26, 12, 18, 6, 11, 5, 10, 9};
-        return DeBruijnBytePos[((U32) ((val & -(S32) val) * 0x077CB531U)) >> 27];
+        return DeBruijnBytePos[((U32) ((val & (0-val)) * 0x077CB531U)) >> 27];
     }
 }
 
diff --git a/lib/common/compiler.h b/lib/common/compiler.h
index 1f7da50e6..944774a7a 100644
--- a/lib/common/compiler.h
+++ b/lib/common/compiler.h
@@ -357,9 +357,9 @@ ptrdiff_t ZSTD_wrappedPtrDiff(unsigned char const* lhs, unsigned char const* rhs
  */
 MEM_STATIC
 ZSTD_ALLOW_POINTER_OVERFLOW_ATTR
-unsigned char const* ZSTD_wrappedPtrAdd(unsigned char const* ptr, ptrdiff_t add)
+const void* ZSTD_wrappedPtrAdd(const void* ptr, ptrdiff_t add)
 {
-    return ptr + add;
+    return (const char*)ptr + add;
 }
 
 /**
@@ -370,9 +370,9 @@ unsigned char const* ZSTD_wrappedPtrAdd(unsigned char const* ptr, ptrdiff_t add)
  */
 MEM_STATIC
 ZSTD_ALLOW_POINTER_OVERFLOW_ATTR
-unsigned char const* ZSTD_wrappedPtrSub(unsigned char const* ptr, ptrdiff_t sub)
+const void* ZSTD_wrappedPtrSub(const void* ptr, ptrdiff_t sub)
 {
-    return ptr - sub;
+    return (const char*)ptr - sub;
 }
 
 /**
@@ -382,9 +382,9 @@ unsigned char const* ZSTD_wrappedPtrSub(unsigned char const* ptr, ptrdiff_t sub)
  * @returns `ptr + add` except it defines `NULL + 0 == NULL`.
  */
 MEM_STATIC
-unsigned char* ZSTD_maybeNullPtrAdd(unsigned char* ptr, ptrdiff_t add)
+void* ZSTD_maybeNullPtrAdd(void* ptr, ptrdiff_t add)
 {
-    return add > 0 ? ptr + add : ptr;
+    return add > 0 ? (char*)ptr + add : ptr;
 }
 
 /* Issue #3240 reports an ASAN failure on an llvm-mingw build. Out of an
diff --git a/lib/common/zstd_internal.h b/lib/common/zstd_internal.h
index 2789a3591..c1647689b 100644
--- a/lib/common/zstd_internal.h
+++ b/lib/common/zstd_internal.h
@@ -213,7 +213,7 @@ typedef enum {
  *           The src buffer must be before the dst buffer.
  */
 MEM_STATIC FORCE_INLINE_ATTR
-void ZSTD_wildcopy(void* dst, const void* src, ptrdiff_t length, ZSTD_overlap_e const ovtype)
+void ZSTD_wildcopy(void* dst, const void* src, size_t length, ZSTD_overlap_e const ovtype)
 {
     ptrdiff_t diff = (BYTE*)dst - (const BYTE*)src;
     const BYTE* ip = (const BYTE*)src;
diff --git a/lib/compress/zstd_compress_internal.h b/lib/compress/zstd_compress_internal.h
index ca5e2a4c5..90202003f 100644
--- a/lib/compress/zstd_compress_internal.h
+++ b/lib/compress/zstd_compress_internal.h
@@ -707,7 +707,7 @@ ZSTD_safecopyLiterals(BYTE* op, BYTE const* ip, BYTE const* const iend, BYTE con
 {
     assert(iend > ilimit_w);
     if (ip <= ilimit_w) {
-        ZSTD_wildcopy(op, ip, ilimit_w - ip, ZSTD_no_overlap);
+        ZSTD_wildcopy(op, ip, (size_t)(ilimit_w - ip), ZSTD_no_overlap);
         op += ilimit_w - ip;
         ip = ilimit_w;
     }
@@ -800,7 +800,7 @@ ZSTD_storeSeq(SeqStore_t* seqStorePtr,
         ZSTD_STATIC_ASSERT(WILDCOPY_OVERLENGTH >= 16);
         ZSTD_copy16(seqStorePtr->lit, literals);
         if (litLength > 16) {
-            ZSTD_wildcopy(seqStorePtr->lit+16, literals+16, (ptrdiff_t)litLength-16, ZSTD_no_overlap);
+            ZSTD_wildcopy(seqStorePtr->lit+16, literals+16, litLength-16, ZSTD_no_overlap);
         }
     } else {
         ZSTD_safecopyLiterals(seqStorePtr->lit, literals, litEnd, litLimit_w);
diff --git a/lib/decompress/huf_decompress.c b/lib/decompress/huf_decompress.c
index f85dd0bee..c7e342648 100644
--- a/lib/decompress/huf_decompress.c
+++ b/lib/decompress/huf_decompress.c
@@ -15,6 +15,7 @@
 /* **************************************************************
 *  Dependencies
 ****************************************************************/
+#include <stddef.h>               /* size_t */
 #include "../common/zstd_deps.h"  /* ZSTD_memcpy, ZSTD_memset */
 #include "../common/compiler.h"
 #include "../common/bitstream.h"  /* BIT_* */
@@ -195,7 +196,7 @@ static size_t HUF_DecompressFastArgs_init(HUF_DecompressFastArgs* args, void* ds
 
     const BYTE* const istart = (const BYTE*)src;
 
-    BYTE* const oend = ZSTD_maybeNullPtrAdd((BYTE*)dst, dstSize);
+    BYTE* const oend = (BYTE*)ZSTD_maybeNullPtrAdd(dst, (ptrdiff_t)dstSize);
 
     /* The fast decoding loop assumes 64-bit little-endian.
      * This condition is false on x32.
@@ -578,7 +579,7 @@ HUF_decompress1X1_usingDTable_internal_body(
     const HUF_DTable* DTable)
 {
     BYTE* op = (BYTE*)dst;
-    BYTE* const oend = ZSTD_maybeNullPtrAdd(op, dstSize);
+    BYTE* const oend = (BYTE*)ZSTD_maybeNullPtrAdd(op, (ptrdiff_t)dstSize);
     const void* dtPtr = DTable + 1;
     const HUF_DEltX1* const dt = (const HUF_DEltX1*)dtPtr;
     BIT_DStream_t bitD;
@@ -845,7 +846,7 @@ HUF_decompress4X1_usingDTable_internal_fast(
 {
     void const* dt = DTable + 1;
     BYTE const* const ilowest = (BYTE const*)cSrc;
-    BYTE* const oend = ZSTD_maybeNullPtrAdd((BYTE*)dst, dstSize);
+    BYTE* const oend = (BYTE*)ZSTD_maybeNullPtrAdd(dst, (ptrdiff_t)dstSize);
     HUF_DecompressFastArgs args;
     {   size_t const ret = HUF_DecompressFastArgs_init(&args, dst, dstSize, cSrc, cSrcSize, DTable);
         FORWARD_IF_ERROR(ret, "Failed to init fast loop args");
@@ -1362,7 +1363,7 @@ HUF_decompress1X2_usingDTable_internal_body(
 
     /* decode */
     {   BYTE* const ostart = (BYTE*) dst;
-        BYTE* const oend = ZSTD_maybeNullPtrAdd(ostart, dstSize);
+        BYTE* const oend = (BYTE*)ZSTD_maybeNullPtrAdd(ostart, (ptrdiff_t)dstSize);
         const void* const dtPtr = DTable+1;   /* force compiler to not use strict-aliasing */
         const HUF_DEltX2* const dt = (const HUF_DEltX2*)dtPtr;
         DTableDesc const dtd = HUF_getDTableDesc(DTable);
@@ -1671,7 +1672,7 @@ HUF_decompress4X2_usingDTable_internal_fast(
     HUF_DecompressFastLoopFn loopFn) {
     void const* dt = DTable + 1;
     const BYTE* const ilowest = (const BYTE*)cSrc;
-    BYTE* const oend = ZSTD_maybeNullPtrAdd((BYTE*)dst, dstSize);
+    BYTE* const oend = (BYTE*)ZSTD_maybeNullPtrAdd(dst, (ptrdiff_t)dstSize);
     HUF_DecompressFastArgs args;
     {
         size_t const ret = HUF_DecompressFastArgs_init(&args, dst, dstSize, cSrc, cSrcSize, DTable);
diff --git a/lib/decompress/zstd_decompress_block.c b/lib/decompress/zstd_decompress_block.c
index 862785a49..3a8e634f9 100644
--- a/lib/decompress/zstd_decompress_block.c
+++ b/lib/decompress/zstd_decompress_block.c
@@ -16,14 +16,13 @@
 *********************************************************/
 #include "../common/zstd_deps.h"   /* ZSTD_memcpy, ZSTD_memmove, ZSTD_memset */
 #include "../common/compiler.h"    /* prefetch */
-#include "../common/cpu.h"         /* bmi2 */
 #include "../common/mem.h"         /* low level memory routines */
+#include <stddef.h>
 #define FSE_STATIC_LINKING_ONLY
 #include "../common/fse.h"
 #include "../common/huf.h"
 #include "../common/zstd_internal.h"
 #include "zstd_decompress_internal.h"   /* ZSTD_DCtx */
-#include "zstd_ddict.h"  /* ZSTD_DDictDictContent */
 #include "zstd_decompress_block.h"
 #include "../common/bits.h"  /* ZSTD_highbit32 */
 
@@ -734,9 +733,10 @@ size_t ZSTD_decodeSeqHeaders(ZSTD_DCtx* dctx, int* nbSeqPtr,
         ip++;
 
         /* Build DTables */
+        assert(ip <= iend);
         {   size_t const llhSize = ZSTD_buildSeqTable(dctx->entropy.LLTable, &dctx->LLTptr,
                                                       LLtype, MaxLL, LLFSELog,
-                                                      ip, iend-ip,
+                                                      ip, (size_t)(iend-ip),
                                                       LL_base, LL_bits,
                                                       LL_defaultDTable, dctx->fseEntropy,
                                                       dctx->ddictIsCold, nbSeq,
@@ -746,9 +746,10 @@ size_t ZSTD_decodeSeqHeaders(ZSTD_DCtx* dctx, int* nbSeqPtr,
             ip += llhSize;
         }
 
+        assert(ip <= iend);
         {   size_t const ofhSize = ZSTD_buildSeqTable(dctx->entropy.OFTable, &dctx->OFTptr,
                                                       OFtype, MaxOff, OffFSELog,
-                                                      ip, iend-ip,
+                                                      ip, (size_t)(iend-ip),
                                                       OF_base, OF_bits,
                                                       OF_defaultDTable, dctx->fseEntropy,
                                                       dctx->ddictIsCold, nbSeq,
@@ -758,9 +759,10 @@ size_t ZSTD_decodeSeqHeaders(ZSTD_DCtx* dctx, int* nbSeqPtr,
             ip += ofhSize;
         }
 
+        assert(ip <= iend);
         {   size_t const mlhSize = ZSTD_buildSeqTable(dctx->entropy.MLTable, &dctx->MLTptr,
                                                       MLtype, MaxML, MLFSELog,
-                                                      ip, iend-ip,
+                                                      ip, (size_t)(iend-ip),
                                                       ML_base, ML_bits,
                                                       ML_defaultDTable, dctx->fseEntropy,
                                                       dctx->ddictIsCold, nbSeq,
@@ -771,7 +773,7 @@ size_t ZSTD_decodeSeqHeaders(ZSTD_DCtx* dctx, int* nbSeqPtr,
         }
     }
 
-    return ip-istart;
+    return (size_t)(ip-istart);
 }
 
 
@@ -801,7 +803,8 @@ typedef struct {
  *  Precondition: *ip <= *op
  *  Postcondition: *op - *op >= 8
  */
-HINT_INLINE void ZSTD_overlapCopy8(BYTE** op, BYTE const** ip, size_t offset) {
+HINT_INLINE void ZSTD_overlapCopy8(BYTE** op, BYTE const** ip, size_t offset)
+{
     assert(*ip <= *op);
     if (offset < 8) {
         /* close range match, overlap */
@@ -834,7 +837,9 @@ HINT_INLINE void ZSTD_overlapCopy8(BYTE** op, BYTE const** ip, size_t offset) {
  *         - ZSTD_overlap_src_before_dst: The src and dst may overlap and may be any distance apart.
  *           The src buffer must be before the dst buffer.
  */
-static void ZSTD_safecopy(BYTE* op, const BYTE* const oend_w, BYTE const* ip, ptrdiff_t length, ZSTD_overlap_e ovtype) {
+static void
+ZSTD_safecopy(BYTE* op, const BYTE* const oend_w, BYTE const* ip, size_t length, ZSTD_overlap_e ovtype)
+{
     ptrdiff_t const diff = op - ip;
     BYTE* const oend = op + length;
 
@@ -849,7 +854,8 @@ static void ZSTD_safecopy(BYTE* op, const BYTE* const oend_w, BYTE const* ip, pt
     if (ovtype == ZSTD_overlap_src_before_dst) {
         /* Copy 8 bytes and ensure the offset >= 8 when there can be overlap. */
         assert(length >= 8);
-        ZSTD_overlapCopy8(&op, &ip, diff);
+        assert(diff > 0);
+        ZSTD_overlapCopy8(&op, &ip, (size_t)diff);
         length -= 8;
         assert(op - ip >= 8);
         assert(op <= oend);
@@ -863,7 +869,7 @@ static void ZSTD_safecopy(BYTE* op, const BYTE* const oend_w, BYTE const* ip, pt
     if (op <= oend_w) {
         /* Wildcopy until we get close to the end. */
         assert(oend > oend_w);
-        ZSTD_wildcopy(op, ip, oend_w - op, ovtype);
+        ZSTD_wildcopy(op, ip, (size_t)(oend_w - op), ovtype);
         ip += oend_w - op;
         op += oend_w - op;
     }
@@ -874,7 +880,8 @@ static void ZSTD_safecopy(BYTE* op, const BYTE* const oend_w, BYTE const* ip, pt
 /* ZSTD_safecopyDstBeforeSrc():
  * This version allows overlap with dst before src, or handles the non-overlap case with dst after src
  * Kept separate from more common ZSTD_safecopy case to avoid performance impact to the safecopy common case */
-static void ZSTD_safecopyDstBeforeSrc(BYTE* op, const BYTE* ip, ptrdiff_t length) {
+static void ZSTD_safecopyDstBeforeSrc(BYTE* op, const BYTE* ip, size_t length)
+{
     ptrdiff_t const diff = op - ip;
     BYTE* const oend = op + length;
 
@@ -885,7 +892,7 @@ static void ZSTD_safecopyDstBeforeSrc(BYTE* op, const BYTE* ip, ptrdiff_t length
     }
 
     if (op <= oend - WILDCOPY_OVERLENGTH && diff < -WILDCOPY_VECLEN) {
-        ZSTD_wildcopy(op, ip, oend - WILDCOPY_OVERLENGTH - op, ZSTD_no_overlap);
+        ZSTD_wildcopy(op, ip, (size_t)(oend - WILDCOPY_OVERLENGTH - op), ZSTD_no_overlap);
         ip += oend - WILDCOPY_OVERLENGTH - op;
         op += oend - WILDCOPY_OVERLENGTH - op;
     }
@@ -936,11 +943,11 @@ size_t ZSTD_execSequenceEnd(BYTE* op,
             return sequenceLength;
         }
         /* span extDict & currentPrefixSegment */
-        {   size_t const length1 = dictEnd - match;
-        ZSTD_memmove(oLitEnd, match, length1);
-        op = oLitEnd + length1;
-        sequence.matchLength -= length1;
-        match = prefixStart;
+        {   size_t const length1 = (size_t)(dictEnd - match);
+            ZSTD_memmove(oLitEnd, match, length1);
+            op = oLitEnd + length1;
+            sequence.matchLength -= length1;
+            match = prefixStart;
         }
     }
     ZSTD_safecopy(op, oend_w, match, sequence.matchLength, ZSTD_overlap_src_before_dst);
@@ -985,11 +992,11 @@ size_t ZSTD_execSequenceEndSplitLitBuffer(BYTE* op,
             return sequenceLength;
         }
         /* span extDict & currentPrefixSegment */
-        {   size_t const length1 = dictEnd - match;
-        ZSTD_memmove(oLitEnd, match, length1);
-        op = oLitEnd + length1;
-        sequence.matchLength -= length1;
-        match = prefixStart;
+        {   size_t const length1 = (size_t)(dictEnd - match);
+            ZSTD_memmove(oLitEnd, match, length1);
+            op = oLitEnd + length1;
+            sequence.matchLength -= length1;
+            match = prefixStart;
         }
     }
     ZSTD_safecopy(op, oend_w, match, sequence.matchLength, ZSTD_overlap_src_before_dst);
@@ -1058,11 +1065,11 @@ size_t ZSTD_execSequence(BYTE* op,
             return sequenceLength;
         }
         /* span extDict & currentPrefixSegment */
-        {   size_t const length1 = dictEnd - match;
-        ZSTD_memmove(oLitEnd, match, length1);
-        op = oLitEnd + length1;
-        sequence.matchLength -= length1;
-        match = prefixStart;
+        {   size_t const length1 = (size_t)(dictEnd - match);
+            ZSTD_memmove(oLitEnd, match, length1);
+            op = oLitEnd + length1;
+            sequence.matchLength -= length1;
+            match = prefixStart;
         }
     }
     /* Match within prefix of 1 or more bytes */
@@ -1079,7 +1086,7 @@ size_t ZSTD_execSequence(BYTE* op,
          * longer than literals (in general). In silesia, ~10% of matches are longer
          * than 16 bytes.
          */
-        ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength, ZSTD_no_overlap);
+        ZSTD_wildcopy(op, match, sequence.matchLength, ZSTD_no_overlap);
         return sequenceLength;
     }
     assert(sequence.offset < WILDCOPY_VECLEN);
@@ -1090,7 +1097,7 @@ size_t ZSTD_execSequence(BYTE* op,
     /* If the match length is > 8 bytes, then continue with the wildcopy. */
     if (sequence.matchLength > 8) {
         assert(op < oMatchEnd);
-        ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength - 8, ZSTD_overlap_src_before_dst);
+        ZSTD_wildcopy(op, match, sequence.matchLength - 8, ZSTD_overlap_src_before_dst);
     }
     return sequenceLength;
 }
@@ -1151,7 +1158,7 @@ size_t ZSTD_execSequenceSplitLitBuffer(BYTE* op,
             return sequenceLength;
         }
         /* span extDict & currentPrefixSegment */
-        {   size_t const length1 = dictEnd - match;
+        {   size_t const length1 = (size_t)(dictEnd - match);
             ZSTD_memmove(oLitEnd, match, length1);
             op = oLitEnd + length1;
             sequence.matchLength -= length1;
@@ -1171,7 +1178,7 @@ size_t ZSTD_execSequenceSplitLitBuffer(BYTE* op,
          * longer than literals (in general). In silesia, ~10% of matches are longer
          * than 16 bytes.
          */
-        ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength, ZSTD_no_overlap);
+        ZSTD_wildcopy(op, match, sequence.matchLength, ZSTD_no_overlap);
         return sequenceLength;
     }
     assert(sequence.offset < WILDCOPY_VECLEN);
@@ -1182,7 +1189,7 @@ size_t ZSTD_execSequenceSplitLitBuffer(BYTE* op,
     /* If the match length is > 8 bytes, then continue with the wildcopy. */
     if (sequence.matchLength > 8) {
         assert(op < oMatchEnd);
-        ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength-8, ZSTD_overlap_src_before_dst);
+        ZSTD_wildcopy(op, match, sequence.matchLength-8, ZSTD_overlap_src_before_dst);
     }
     return sequenceLength;
 }
@@ -1405,10 +1412,8 @@ ZSTD_decompressSequences_bodySplitLitBuffer( ZSTD_DCtx* dctx,
                          const void* seqStart, size_t seqSize, int nbSeq,
                          const ZSTD_longOffset_e isLongOffset)
 {
-    const BYTE* ip = (const BYTE*)seqStart;
-    const BYTE* const iend = ip + seqSize;
     BYTE* const ostart = (BYTE*)dst;
-    BYTE* const oend = ZSTD_maybeNullPtrAdd(ostart, maxDstSize);
+    BYTE* const oend = (BYTE*)ZSTD_maybeNullPtrAdd(ostart, (ptrdiff_t)maxDstSize);
     BYTE* op = ostart;
     const BYTE* litPtr = dctx->litPtr;
     const BYTE* litBufferEnd = dctx->litBufferEnd;
@@ -1423,7 +1428,7 @@ ZSTD_decompressSequences_bodySplitLitBuffer( ZSTD_DCtx* dctx,
         dctx->fseEntropy = 1;
         { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) seqState.prevOffset[i] = dctx->entropy.rep[i]; }
         RETURN_ERROR_IF(
-            ERR_isError(BIT_initDStream(&seqState.DStream, ip, iend-ip)),
+            ERR_isError(BIT_initDStream(&seqState.DStream, seqStart, seqSize)),
             corruption_detected, "");
         ZSTD_initFseState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr);
         ZSTD_initFseState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr);
@@ -1515,7 +1520,8 @@ ZSTD_decompressSequences_bodySplitLitBuffer( ZSTD_DCtx* dctx,
 
             /* If there are more sequences, they will need to read literals from litExtraBuffer; copy over the remainder from dst and update litPtr and litEnd */
             if (nbSeq > 0) {
-                const size_t leftoverLit = dctx->litBufferEnd - litPtr;
+                const size_t leftoverLit = (size_t)(dctx->litBufferEnd - litPtr);
+                assert(dctx->litBufferEnd >= litPtr);
                 DEBUGLOG(6, "There are %i sequences left, and %zu/%zu literals left in buffer", nbSeq, leftoverLit, sequence.litLength);
                 if (leftoverLit) {
                     RETURN_ERROR_IF(leftoverLit > (size_t)(oend - op), dstSize_tooSmall, "remaining lit must fit within dstBuffer");
@@ -1617,10 +1623,10 @@ ZSTD_decompressSequences_body(ZSTD_DCtx* dctx,
     const void* seqStart, size_t seqSize, int nbSeq,
     const ZSTD_longOffset_e isLongOffset)
 {
-    const BYTE* ip = (const BYTE*)seqStart;
-    const BYTE* const iend = ip + seqSize;
     BYTE* const ostart = (BYTE*)dst;
-    BYTE* const oend = dctx->litBufferLocation == ZSTD_not_in_dst ? ZSTD_maybeNullPtrAdd(ostart, maxDstSize) : dctx->litBuffer;
+    BYTE* const oend = (dctx->litBufferLocation == ZSTD_not_in_dst) ?
+                        (BYTE*)ZSTD_maybeNullPtrAdd(ostart, (ptrdiff_t)maxDstSize) :
+                        dctx->litBuffer;
     BYTE* op = ostart;
     const BYTE* litPtr = dctx->litPtr;
     const BYTE* const litEnd = litPtr + dctx->litSize;
@@ -1635,7 +1641,7 @@ ZSTD_decompressSequences_body(ZSTD_DCtx* dctx,
         dctx->fseEntropy = 1;
         { U32 i; for (i = 0; i < ZSTD_REP_NUM; i++) seqState.prevOffset[i] = dctx->entropy.rep[i]; }
         RETURN_ERROR_IF(
-            ERR_isError(BIT_initDStream(&seqState.DStream, ip, iend - ip)),
+            ERR_isError(BIT_initDStream(&seqState.DStream, seqStart, seqSize)),
             corruption_detected, "");
         ZSTD_initFseState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr);
         ZSTD_initFseState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr);
@@ -1719,7 +1725,7 @@ size_t ZSTD_prefetchMatch(size_t prefetchPos, seq_t const sequence,
     {   const BYTE* const matchBase = (sequence.offset > prefetchPos) ? dictEnd : prefixStart;
         /* note : this operation can overflow when seq.offset is really too large, which can only happen when input is corrupted.
          * No consequence though : memory address is only used for prefetching, not for dereferencing */
-        const BYTE* const match = ZSTD_wrappedPtrSub(ZSTD_wrappedPtrAdd(matchBase, prefetchPos), sequence.offset);
+        const BYTE* const match = (const BYTE*)ZSTD_wrappedPtrSub(ZSTD_wrappedPtrAdd(matchBase, (ptrdiff_t)prefetchPos), (ptrdiff_t)sequence.offset);
         PREFETCH_L1(match); PREFETCH_L1(match+CACHELINE_SIZE);   /* note : it's safe to invoke PREFETCH() on any memory address, including invalid ones */
     }
     return prefetchPos + sequence.matchLength;
@@ -1736,10 +1742,10 @@ ZSTD_decompressSequencesLong_body(
                          const void* seqStart, size_t seqSize, int nbSeq,
                          const ZSTD_longOffset_e isLongOffset)
 {
-    const BYTE* ip = (const BYTE*)seqStart;
-    const BYTE* const iend = ip + seqSize;
     BYTE* const ostart = (BYTE*)dst;
-    BYTE* const oend = dctx->litBufferLocation == ZSTD_in_dst ? dctx->litBuffer : ZSTD_maybeNullPtrAdd(ostart, maxDstSize);
+    BYTE* const oend = (dctx->litBufferLocation == ZSTD_in_dst) ?
+                        dctx->litBuffer :
+                        (BYTE*)ZSTD_maybeNullPtrAdd(ostart, (ptrdiff_t)maxDstSize);
     BYTE* op = ostart;
     const BYTE* litPtr = dctx->litPtr;
     const BYTE* litBufferEnd = dctx->litBufferEnd;
@@ -1761,9 +1767,8 @@ ZSTD_decompressSequencesLong_body(
         dctx->fseEntropy = 1;
         { int i; for (i=0; i<ZSTD_REP_NUM; i++) seqState.prevOffset[i] = dctx->entropy.rep[i]; }
         assert(dst != NULL);
-        assert(iend >= ip);
         RETURN_ERROR_IF(
-            ERR_isError(BIT_initDStream(&seqState.DStream, ip, iend-ip)),
+            ERR_isError(BIT_initDStream(&seqState.DStream, seqStart, seqSize)),
             corruption_detected, "");
         ZSTD_initFseState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr);
         ZSTD_initFseState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr);
@@ -1782,9 +1787,9 @@ ZSTD_decompressSequencesLong_body(
 
             if (dctx->litBufferLocation == ZSTD_split && litPtr + sequences[(seqNb - ADVANCED_SEQS) & STORED_SEQS_MASK].litLength > dctx->litBufferEnd) {
                 /* lit buffer is reaching split point, empty out the first buffer and transition to litExtraBuffer */
-                const size_t leftoverLit = dctx->litBufferEnd - litPtr;
-                if (leftoverLit)
-                {
+                const size_t leftoverLit = (size_t)(dctx->litBufferEnd - litPtr);
+                assert(dctx->litBufferEnd >= litPtr);
+                if (leftoverLit) {
                     RETURN_ERROR_IF(leftoverLit > (size_t)(oend - op), dstSize_tooSmall, "remaining lit must fit within dstBuffer");
                     ZSTD_safecopyDstBeforeSrc(op, litPtr, leftoverLit);
                     sequences[(seqNb - ADVANCED_SEQS) & STORED_SEQS_MASK].litLength -= leftoverLit;
@@ -1828,7 +1833,8 @@ ZSTD_decompressSequencesLong_body(
         for ( ; seqNb<nbSeq ; seqNb++) {
             seq_t *sequence = &(sequences[seqNb&STORED_SEQS_MASK]);
             if (dctx->litBufferLocation == ZSTD_split && litPtr + sequence->litLength > dctx->litBufferEnd) {
-                const size_t leftoverLit = dctx->litBufferEnd - litPtr;
+                const size_t leftoverLit = (size_t)(dctx->litBufferEnd - litPtr);
+                assert(dctx->litBufferEnd >= litPtr);
                 if (leftoverLit) {
                     RETURN_ERROR_IF(leftoverLit > (size_t)(oend - op), dstSize_tooSmall, "remaining lit must fit within dstBuffer");
                     ZSTD_safecopyDstBeforeSrc(op, litPtr, leftoverLit);
@@ -1867,7 +1873,8 @@ ZSTD_decompressSequencesLong_body(
 
     /* last literal segment */
     if (dctx->litBufferLocation == ZSTD_split) { /* first deplete literal buffer in dst, then copy litExtraBuffer */
-        size_t const lastLLSize = litBufferEnd - litPtr;
+        size_t const lastLLSize = (size_t)(litBufferEnd - litPtr);
+        assert(litBufferEnd >= litPtr);
         RETURN_ERROR_IF(lastLLSize > (size_t)(oend - op), dstSize_tooSmall, "");
         if (op != NULL) {
             ZSTD_memmove(op, litPtr, lastLLSize);
@@ -1876,7 +1883,8 @@ ZSTD_decompressSequencesLong_body(
         litPtr = dctx->litExtraBuffer;
         litBufferEnd = dctx->litExtraBuffer + ZSTD_LITBUFFEREXTRASIZE;
     }
-    {   size_t const lastLLSize = litBufferEnd - litPtr;
+    {   size_t const lastLLSize = (size_t)(litBufferEnd - litPtr);
+        assert(litBufferEnd >= litPtr);
         RETURN_ERROR_IF(lastLLSize > (size_t)(oend-op), dstSize_tooSmall, "");
         if (op != NULL) {
             ZSTD_memmove(op, litPtr, lastLLSize);
@@ -1993,9 +2001,9 @@ ZSTD_decompressSequencesLong(ZSTD_DCtx* dctx,
  * both the prefix and the extDict. At @p op any offset larger than this
  * is invalid.
  */
-static size_t ZSTD_totalHistorySize(BYTE* op, BYTE const* virtualStart)
+static size_t ZSTD_totalHistorySize(void* curPtr, const void* virtualStart)
 {
-    return (size_t)(op - virtualStart);
+    return (size_t)((char*)curPtr - (const char*)virtualStart);
 }
 
 typedef struct {
@@ -2094,7 +2102,7 @@ ZSTD_decompressBlock_internal(ZSTD_DCtx* dctx,
          * Additionally, take the min with dstCapacity to ensure that the totalHistorySize fits in a size_t.
          */
         size_t const blockSizeMax = MIN(dstCapacity, ZSTD_blockSizeMax(dctx));
-        size_t const totalHistorySize = ZSTD_totalHistorySize(ZSTD_maybeNullPtrAdd((BYTE*)dst, blockSizeMax), (BYTE const*)dctx->virtualStart);
+        size_t const totalHistorySize = ZSTD_totalHistorySize(ZSTD_maybeNullPtrAdd(dst, (ptrdiff_t)blockSizeMax), (BYTE const*)dctx->virtualStart);
         /* isLongOffset must be true if there are long offsets.
          * Offsets are long if they are larger than ZSTD_maxShortOffset().
          * We don't expect that to be the case in 64-bit mode.
diff --git a/lib/dictBuilder/cover.c b/lib/dictBuilder/cover.c
index 2ef33c73e..a71370c72 100644
--- a/lib/dictBuilder/cover.c
+++ b/lib/dictBuilder/cover.c
@@ -1183,7 +1183,7 @@ ZDICTLIB_STATIC_API size_t ZDICT_optimizeTrainFromBuffer_cover(
       (1 + (kMaxD - kMinD) / 2) * (1 + (kMaxK - kMinK) / kStepSize);
   const unsigned shrinkDict = 0;
   /* Local variables */
-  const int displayLevel = parameters->zParams.notificationLevel;
+  const int displayLevel = (int)parameters->zParams.notificationLevel;
   unsigned iteration = 1;
   unsigned d;
   unsigned k;
@@ -1261,7 +1261,7 @@ ZDICTLIB_STATIC_API size_t ZDICT_optimizeTrainFromBuffer_cover(
       data->parameters.splitPoint = splitPoint;
       data->parameters.steps = kSteps;
       data->parameters.shrinkDict = shrinkDict;
-      data->parameters.zParams.notificationLevel = g_displayLevel;
+      data->parameters.zParams.notificationLevel = (unsigned)g_displayLevel;
       /* Check the parameters */
       if (!COVER_checkParameters(data->parameters, dictBufferCapacity)) {
         DISPLAYLEVEL(1, "Cover parameters incorrect\n");
diff --git a/lib/dictBuilder/divsufsort.c b/lib/dictBuilder/divsufsort.c
index a2870fb3b..e5b117b29 100644
--- a/lib/dictBuilder/divsufsort.c
+++ b/lib/dictBuilder/divsufsort.c
@@ -199,8 +199,8 @@ ss_isqrt(int x) {
   int y, e;
 
   if(x >= (SS_BLOCKSIZE * SS_BLOCKSIZE)) { return SS_BLOCKSIZE; }
-  e = (x & 0xffff0000) ?
-        ((x & 0xff000000) ?
+  e = ((unsigned)x & 0xffff0000) ?
+        (((unsigned)x & 0xff000000) ?
           24 + lg_table[(x >> 24) & 0xff] :
           16 + lg_table[(x >> 16) & 0xff]) :
         ((x & 0x0000ff00) ?
@@ -909,8 +909,8 @@ sssort(const unsigned char *T, const int *PA,
 static INLINE
 int
 tr_ilg(int n) {
-  return (n & 0xffff0000) ?
-          ((n & 0xff000000) ?
+  return ((unsigned)n & 0xffff0000) ?
+          (((unsigned)n & 0xff000000) ?
             24 + lg_table[(n >> 24) & 0xff] :
             16 + lg_table[(n >> 16) & 0xff]) :
           ((n & 0x0000ff00) ?
diff --git a/lib/dictBuilder/zdict.c b/lib/dictBuilder/zdict.c
index d5e60a4da..befa616b8 100644
--- a/lib/dictBuilder/zdict.c
+++ b/lib/dictBuilder/zdict.c
@@ -168,7 +168,7 @@ static void ZDICT_initDictItem(dictItem* d)
 #define MINMATCHLENGTH 7   /* heuristic determined experimentally */
 static dictItem ZDICT_analyzePos(
                        BYTE* doneMarks,
-                       const int* suffix, U32 start,
+                       const unsigned* suffix, U32 start,
                        const void* buffer, U32 minRatio, U32 notificationLevel)
 {
     U32 lengthList[LLIMIT] = {0};
@@ -293,8 +293,10 @@ static dictItem ZDICT_analyzePos(
         for (i=(int)(maxLength-2); i>=0; i--)
             cumulLength[i] = cumulLength[i+1] + lengthList[i];
 
-        for (i=LLIMIT-1; i>=MINMATCHLENGTH; i--) if (cumulLength[i]>=minRatio) break;
-        maxLength = i;
+        {   unsigned u;
+            for (u=LLIMIT-1; u>=MINMATCHLENGTH; u--) if (cumulLength[u]>=minRatio) break;
+            maxLength = u;
+        }
 
         /* reduce maxLength in case of final into repetitive data */
         {   U32 l = (U32)maxLength;
@@ -306,8 +308,10 @@ static dictItem ZDICT_analyzePos(
 
         /* calculate savings */
         savings[5] = 0;
-        for (i=MINMATCHLENGTH; i<=(int)maxLength; i++)
-            savings[i] = savings[i-1] + (lengthList[i] * (i-3));
+        {   unsigned u;
+            for (u=MINMATCHLENGTH; u<=maxLength; u++)
+                savings[u] = savings[u-1] + (lengthList[u] * (u-3));
+        }
 
         DISPLAYLEVEL(4, "Selected dict at position %u, of length %u : saves %u (ratio: %.2f)  \n",
                      (unsigned)pos, (unsigned)maxLength, (unsigned)savings[maxLength], (double)savings[maxLength] / (double)maxLength);
@@ -383,11 +387,11 @@ static U32 ZDICT_tryMerge(dictItem* table, dictItem elt, U32 eltNbToSkip, const
 
         if ((table[u].pos + table[u].length >= elt.pos) && (table[u].pos < elt.pos)) {  /* overlap, existing < new */
             /* append */
-            int const addedLength = (int)eltEnd - (int)(table[u].pos + table[u].length);
+            int const addedLength = (int)eltEnd - (int)(table[u].pos + table[u].length); /* note: can be negative */
             table[u].savings += elt.length / 8;    /* rough approx bonus */
             if (addedLength > 0) {   /* otherwise, elt fully included into existing */
-                table[u].length += addedLength;
-                table[u].savings += elt.savings * addedLength / elt.length;   /* rough approx */
+                table[u].length += (unsigned)addedLength;
+                table[u].savings += elt.savings * (unsigned)addedLength / elt.length;   /* rough approx */
             }
             /* sort : improve rank */
             elt = table[u];
@@ -399,7 +403,7 @@ static U32 ZDICT_tryMerge(dictItem* table, dictItem elt, U32 eltNbToSkip, const
 
         if (MEM_read64(buf + table[u].pos) == MEM_read64(buf + elt.pos + 1)) {
             if (isIncluded(buf + table[u].pos, buf + elt.pos + 1, table[u].length)) {
-                size_t const addedLength = MAX( (int)elt.length - (int)table[u].length , 1 );
+                size_t const addedLength = MAX( elt.length - table[u].length , 1 );
                 table[u].pos = elt.pos;
                 table[u].savings += (U32)(elt.savings * addedLength / elt.length);
                 table[u].length = MIN(elt.length, table[u].length + 1);
@@ -467,8 +471,8 @@ static size_t ZDICT_trainBuffer_legacy(dictItem* dictList, U32 dictListSize,
                             const size_t* fileSizes, unsigned nbFiles,
                             unsigned minRatio, U32 notificationLevel)
 {
-    int* const suffix0 = (int*)malloc((bufferSize+2)*sizeof(*suffix0));
-    int* const suffix = suffix0+1;
+    unsigned* const suffix0 = (unsigned*)malloc((bufferSize+2)*sizeof(*suffix0));
+    unsigned* const suffix = suffix0+1;
     U32* reverseSuffix = (U32*)malloc((bufferSize)*sizeof(*reverseSuffix));
     BYTE* doneMarks = (BYTE*)malloc((bufferSize+16)*sizeof(*doneMarks));   /* +16 for overflow security */
     U32* filePos = (U32*)malloc(nbFiles * sizeof(*filePos));
@@ -503,11 +507,11 @@ static size_t ZDICT_trainBuffer_legacy(dictItem* dictList, U32 dictListSize,
 
     /* sort */
     DISPLAYLEVEL(2, "sorting %u files of total size %u MB ...\n", nbFiles, (unsigned)(bufferSize>>20));
-    {   int const divSuftSortResult = divsufsort((const unsigned char*)buffer, suffix, (int)bufferSize, 0);
+    {   int const divSuftSortResult = divsufsort((const unsigned char*)buffer, (int*)suffix, (int)bufferSize, 0);
         if (divSuftSortResult != 0) { result = ERROR(GENERIC); goto _cleanup; }
     }
-    suffix[bufferSize] = (int)bufferSize;   /* leads into noise */
-    suffix0[0] = (int)bufferSize;           /* leads into noise */
+    suffix[bufferSize] = (unsigned)bufferSize;   /* leads into noise */
+    suffix0[0] = (unsigned)bufferSize;           /* leads into noise */
     /* build reverse suffix sort */
     {   size_t pos;
         for (pos=0; pos < bufferSize; pos++)