[Branch-Rename] Fix some links

According to the [[ https://foundation.llvm.org/docs/branch-rename/ | status of branch rename ]], the master branch of the LLVM repository is removed on 28 Jan 2021.

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D95766

docs/Vectorizers.rst

@@ -393,7 +393,7 @@ Performance
 -----------
 
 This section shows the execution time of Clang on a simple benchmark:
-`gcc-loops <https://github.com/llvm/llvm-test-suite/tree/master/SingleSource/UnitTests/Vectorizer>`_.
+`gcc-loops <https://github.com/llvm/llvm-test-suite/tree/main/SingleSource/UnitTests/Vectorizer>`_.
 This benchmarks is a collection of loops from the GCC autovectorization
 `page <http://gcc.gnu.org/projects/tree-ssa/vectorization.html>`_ by Dorit Nuzman.
 

lib/CodeGen/GlobalISel/LegalizerHelper.cpp

@@ -5242,7 +5242,7 @@ LegalizerHelper::LegalizeResult LegalizerHelper::lowerFPTOSI(MachineInstr &MI) {
 
   // Expand f32 -> i64 conversion
   // This algorithm comes from compiler-rt's implementation of fixsfdi:
-  // https://github.com/llvm/llvm-project/blob/master/compiler-rt/lib/builtins/fixsfdi.c
+  // https://github.com/llvm/llvm-project/blob/main/compiler-rt/lib/builtins/fixsfdi.c
 
   unsigned SrcEltBits = SrcTy.getScalarSizeInBits();
 

lib/CodeGen/SelectionDAG/TargetLowering.cpp

@@ -6514,7 +6514,7 @@ bool TargetLowering::expandFP_TO_SINT(SDNode *Node, SDValue &Result,
 
   // Expand f32 -> i64 conversion
   // This algorithm comes from compiler-rt's implementation of fixsfdi:
-  // https://github.com/llvm/llvm-project/blob/master/compiler-rt/lib/builtins/fixsfdi.c
+  // https://github.com/llvm/llvm-project/blob/main/compiler-rt/lib/builtins/fixsfdi.c
   unsigned SrcEltBits = SrcVT.getScalarSizeInBits();
   EVT IntVT = SrcVT.changeTypeToInteger();
   EVT IntShVT = getShiftAmountTy(IntVT, DAG.getDataLayout());

test/Transforms/SLPVectorizer/AArch64/matmul.ll

@@ -4,7 +4,7 @@
 target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
 
 ; This test is reduced from the matrix multiplication benchmark in the test-suite:
-; https://github.com/llvm/llvm-test-suite/tree/master/SingleSource/Benchmarks/Misc/matmul_f64_4x4.c
+; https://github.com/llvm/llvm-test-suite/tree/main/SingleSource/Benchmarks/Misc/matmul_f64_4x4.c
 ; The operations here are expected to be vectorized to <2 x double>.
 ; Otherwise, performance will suffer on Cortex-A53.
 

utils/lit/setup.py

@@ -54,7 +54,7 @@ Source
 ======
 
 The *lit* source is available as part of LLVM, in the LLVM source repository:
-https://github.com/llvm/llvm-project/tree/master/llvm/utils/lit
+https://github.com/llvm/llvm-project/tree/main/llvm/utils/lit
 """,
 
     classifiers=[