[clang] a5cd202 - Use llvm::Log2_32 and llvm::Log2_64 instead of llvm::findLastSet (NFC)

[Kazu Hirata via cfe-commits]

Author: Kazu Hirata
Date: 2023-01-25T21:34:09-08:00
New Revision: a5cd202e21e52c1e00963ad5bdfeb83b4fec820e

URL: https://github.com/llvm/llvm-project/commit/a5cd202e21e52c1e00963ad5bdfeb83b4fec820e
DIFF: https://github.com/llvm/llvm-project/commit/a5cd202e21e52c1e00963ad5bdfeb83b4fec820e.diff

LOG: Use llvm::Log2_32 and llvm::Log2_64 instead of llvm::findLastSet (NFC)

For a nonzero argument, llvm::findLastSet(x) is equivalent to
llvm::Log2_32(x) or llvm::Log2_64(x).  None of the calls to
llvm::findLastSet in this patch relies on llvm::findLastSet's ability
to return std::numeric_limits<T>::max() on input 0.

Added: 
    

Modified: 
    clang-tools-extra/clangd/index/dex/PostingList.cpp
    clang/lib/CodeGen/SwiftCallingConv.cpp
    llvm/lib/Target/AArch64/AArch64ISelDAGToDAG.cpp
    llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp

Removed: 
    


################################################################################
diff  --git a/clang-tools-extra/clangd/index/dex/PostingList.cpp b/clang-tools-extra/clangd/index/dex/PostingList.cpp
index c02d52734972b..691975d2f2244 100644
--- a/clang-tools-extra/clangd/index/dex/PostingList.cpp
+++ b/clang-tools-extra/clangd/index/dex/PostingList.cpp
@@ -132,7 +132,7 @@ bool encodeVByte(DocID Delta, llvm::MutableArrayRef<uint8_t> &Payload) {
   assert(Delta != 0 && "0 is not a valid PostingList delta.");
   // Calculate number of bytes Delta encoding would take by examining the
   // meaningful bits.
-  unsigned Width = 1 + llvm::findLastSet(Delta) / BitsPerEncodingByte;
+  unsigned Width = 1 + llvm::Log2_64(Delta) / BitsPerEncodingByte;
   if (Width > Payload.size())
     return false;
 

diff  --git a/clang/lib/CodeGen/SwiftCallingConv.cpp b/clang/lib/CodeGen/SwiftCallingConv.cpp
index 63d975193c027..055dd37043866 100644
--- a/clang/lib/CodeGen/SwiftCallingConv.cpp
+++ b/clang/lib/CodeGen/SwiftCallingConv.cpp
@@ -728,7 +728,7 @@ void swiftcall::legalizeVectorType(CodeGenModule &CGM, CharUnits origVectorSize,
 
   // The largest size that we're still considering making subvectors of.
   // Always a power of 2.
-  unsigned logCandidateNumElts = llvm::findLastSet(numElts, llvm::ZB_Undefined);
+  unsigned logCandidateNumElts = llvm::Log2_32(numElts);
   unsigned candidateNumElts = 1U << logCandidateNumElts;
   assert(candidateNumElts <= numElts && candidateNumElts * 2 > numElts);
 

diff  --git a/llvm/lib/Target/AArch64/AArch64ISelDAGToDAG.cpp b/llvm/lib/Target/AArch64/AArch64ISelDAGToDAG.cpp
index 22d11a96a8646..78adb143453ee 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelDAGToDAG.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelDAGToDAG.cpp
@@ -2328,7 +2328,7 @@ static bool isSeveralBitsExtractOpFromShr(SDNode *N, unsigned &Opc,
   //
   // This gets selected into a single UBFM:
   //
-  // UBFM Value, ShiftImm, findLastSet(MaskImm)
+  // UBFM Value, ShiftImm, Log2_64(MaskImm)
   //
 
   if (N->getOpcode() != ISD::SRL)
@@ -2350,7 +2350,7 @@ static bool isSeveralBitsExtractOpFromShr(SDNode *N, unsigned &Opc,
 
   Opc = N->getValueType(0) == MVT::i32 ? AArch64::UBFMWri : AArch64::UBFMXri;
   LSB = SrlImm;
-  MSB = findLastSet(AndMask, ZB_Undefined);
+  MSB = llvm::Log2_64(AndMask);
   return true;
 }
 

diff  --git a/llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp b/llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp
index c916d5d547c44..9035ae6f7e396 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp
@@ -761,7 +761,7 @@ void AMDGPUAsmPrinter::getSIProgramInfo(SIProgramInfo &ProgInfo,
       // There are some rare circumstances where InputAddr is non-zero and
       // InputEna can be set to 0. In this case we default to setting LastEna
       // to 1.
-      LastEna = InputEna ? findLastSet(InputEna) + 1 : 1;
+      LastEna = InputEna ? llvm::Log2_32(InputEna) + 1 : 1;
     }
 
     // FIXME: We should be using the number of registers determined during