[llvm] bf60a1c - Avoid comparisons between types of different widths in a loop condition to prevent the loop from behaving unexpectedly

[via llvm-commits]

Author: Aakanksha
Date: 2022-02-25T17:30:12Z
New Revision: bf60a1c546ee496c1dd9336f2a2d8ea989c49558

URL: https://github.com/llvm/llvm-project/commit/bf60a1c546ee496c1dd9336f2a2d8ea989c49558
DIFF: https://github.com/llvm/llvm-project/commit/bf60a1c546ee496c1dd9336f2a2d8ea989c49558.diff

LOG: Avoid comparisons between types of different widths in a loop condition to prevent the loop from behaving unexpectedly

This change fixes the code violations flagged in AMD compute CodeQL scan -
Query Description: "Comparisons between types of different widths in a loop condition can cause the loop to behave unexpectedly."

Differential Revision: https://reviews.llvm.org/D120355

Added: 
    

Modified: 
    llvm/lib/Target/AMDGPU/SIRegisterInfo.cpp
    llvm/tools/llvm-pdbutil/DumpOutputStyle.cpp
    llvm/tools/llvm-pdbutil/StreamUtil.cpp
    llvm/utils/TableGen/X86RecognizableInstr.cpp

Removed: 
    


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diff  --git a/llvm/lib/Target/AMDGPU/SIRegisterInfo.cpp b/llvm/lib/Target/AMDGPU/SIRegisterInfo.cpp
index 9ce83a65dd0d8..d2622d116d5c1 100644
--- a/llvm/lib/Target/AMDGPU/SIRegisterInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/SIRegisterInfo.cpp
@@ -357,7 +357,7 @@ SIRegisterInfo::SIRegisterInfo(const GCNSubtarget &ST)
   static auto InitializeSubRegFromChannelTableOnce = [this]() {
     for (auto &Row : SubRegFromChannelTable)
       Row.fill(AMDGPU::NoSubRegister);
-    for (uint16_t Idx = 1; Idx < getNumSubRegIndices(); ++Idx) {
+    for (unsigned Idx = 1; Idx < getNumSubRegIndices(); ++Idx) {
       unsigned Width = AMDGPUSubRegIdxRanges[Idx].Size / 32;
       unsigned Offset = AMDGPUSubRegIdxRanges[Idx].Offset / 32;
       assert(Width < SubRegFromChannelTableWidthMap.size());

diff  --git a/llvm/tools/llvm-pdbutil/DumpOutputStyle.cpp b/llvm/tools/llvm-pdbutil/DumpOutputStyle.cpp
index ef299ea9d4825..0e4f103d08c62 100644
--- a/llvm/tools/llvm-pdbutil/DumpOutputStyle.cpp
+++ b/llvm/tools/llvm-pdbutil/DumpOutputStyle.cpp
@@ -389,7 +389,7 @@ Error DumpOutputStyle::dumpStreamSummary() {
   uint32_t StreamCount = getPdb().getNumStreams();
   uint32_t MaxStreamSize = getPdb().getMaxStreamSize();
 
-  for (uint16_t StreamIdx = 0; StreamIdx < StreamCount; ++StreamIdx) {
+  for (uint32_t StreamIdx = 0; StreamIdx < StreamCount; ++StreamIdx) {
     P.formatLine(
         "Stream {0} ({1} bytes): [{2}]",
         fmt_align(StreamIdx, AlignStyle::Right, NumDigits(StreamCount)),

diff  --git a/llvm/tools/llvm-pdbutil/StreamUtil.cpp b/llvm/tools/llvm-pdbutil/StreamUtil.cpp
index d0d0a9fbe9275..de906f9064f47 100644
--- a/llvm/tools/llvm-pdbutil/StreamUtil.cpp
+++ b/llvm/tools/llvm-pdbutil/StreamUtil.cpp
@@ -95,7 +95,7 @@ void llvm::pdb::discoverStreamPurposes(PDBFile &File,
   }
 
   Streams.resize(StreamCount);
-  for (uint16_t StreamIdx = 0; StreamIdx < StreamCount; ++StreamIdx) {
+  for (uint32_t StreamIdx = 0; StreamIdx < StreamCount; ++StreamIdx) {
     if (StreamIdx == OldMSFDirectory)
       Streams[StreamIdx] =
           stream(StreamPurpose::Other, "Old MSF Directory", StreamIdx);

diff  --git a/llvm/utils/TableGen/X86RecognizableInstr.cpp b/llvm/utils/TableGen/X86RecognizableInstr.cpp
index 4023d8f57318e..ae01014ddd235 100644
--- a/llvm/utils/TableGen/X86RecognizableInstr.cpp
+++ b/llvm/utils/TableGen/X86RecognizableInstr.cpp
@@ -835,7 +835,7 @@ void RecognizableInstr::emitDecodePath(DisassemblerTables &tables) const {
   if (Form == X86Local::AddRegFrm || Form == X86Local::MRMSrcRegCC ||
       Form == X86Local::MRMSrcMemCC || Form == X86Local::MRMXrCC ||
       Form == X86Local::MRMXmCC || Form == X86Local::AddCCFrm) {
-    unsigned Count = Form == X86Local::AddRegFrm ? 8 : 16;
+    uint8_t Count = Form == X86Local::AddRegFrm ? 8 : 16;
     assert(((opcodeToSet % Count) == 0) && "ADDREG_FRM opcode not aligned");
 
     uint8_t currentOpcode;