[llvm] 85c7a7f - [DirectX] Don't byte-swap returned byte-offset (#155860)

[via llvm-commits]

Author: Finn Plummer
Date: 2025-08-28T09:59:38-07:00
New Revision: 85c7a7f3b8d9856e6d1e3c63e3a7e387367ed072

URL: https://github.com/llvm/llvm-project/commit/85c7a7f3b8d9856e6d1e3c63e3a7e387367ed072
DIFF: https://github.com/llvm/llvm-project/commit/85c7a7f3b8d9856e6d1e3c63e3a7e387367ed072.diff

LOG: [DirectX] Don't byte-swap returned byte-offset (#155860)

- The returned byte offset from `rewriteOffsetToCurrentByte` should not
be byte-swapped as it will be compared and interpreted as a uint32_t in
its uses

This commit corrects build failures that hit an assert on big-endian
builds

Added: 
    

Modified: 
    llvm/lib/MC/DXContainerRootSignature.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/MC/DXContainerRootSignature.cpp b/llvm/lib/MC/DXContainerRootSignature.cpp
index 3513892ffcdcc..4d5322b5b3cbe 100644
--- a/llvm/lib/MC/DXContainerRootSignature.cpp
+++ b/llvm/lib/MC/DXContainerRootSignature.cpp
@@ -22,11 +22,12 @@ static uint32_t writePlaceholder(raw_svector_ostream &Stream) {
 
 static uint32_t rewriteOffsetToCurrentByte(raw_svector_ostream &Stream,
                                            uint32_t Offset) {
+  uint32_t ByteOffset = Stream.tell();
   uint32_t Value =
       support::endian::byte_swap<uint32_t, llvm::endianness::little>(
-          Stream.tell());
+          ByteOffset);
   Stream.pwrite(reinterpret_cast<const char *>(&Value), sizeof(Value), Offset);
-  return Value;
+  return ByteOffset;
 }
 
 size_t RootSignatureDesc::getSize() const {