Merge branch 'main' of https://github.com/llvm/llvm-project into index-to-i1

Author: ianayl

lld/test/MachO/objc-category-merging-minimal.s

@@ -33,7 +33,7 @@
 
 ############ Test merging skipped due to invalid category name ############
 # Modify __OBJC_$_CATEGORY_MyBaseClass_$_Category01's name to point to L_OBJC_IMAGE_INFO+3
-# RUN: awk '/^__OBJC_\$_CATEGORY_MyBaseClass_\$_Category01:/ { print; getline; sub(/^[ \t]*\.quad[ \t]+l_OBJC_CLASS_NAME_$/, "\t.quad\tL_OBJC_IMAGE_INFO+3"); print; next } { print }' merge_cat_minimal.s > merge_cat_minimal_bad_name.s
+# RUN: awk '/^__OBJC_\\$_CATEGORY_MyBaseClass_\\$_Category01:/ { print; getline; sub(/^[ \t]*\.quad[ \t]+l_OBJC_CLASS_NAME_$/, "\t.quad\tL_OBJC_IMAGE_INFO+3"); print; next } { print }' merge_cat_minimal.s > merge_cat_minimal_bad_name.s
 
 # Assemble the modified source
 # RUN: llvm-mc -filetype=obj -triple=arm64-apple-macos -o merge_cat_minimal_bad_name.o merge_cat_minimal_bad_name.s

lld/test/lit.cfg.py

@@ -16,10 +16,21 @@
 # name: The name of this test suite.
 config.name = "lld"
 
+# TODO: Consolidate the logic for turning on the internal shell by default for all LLVM test suites.
+# See https://github.com/llvm/llvm-project/issues/106636 for more details.
+#
+# We prefer the lit internal shell which provides a better user experience on failures
+# and is faster unless the user explicitly disables it with LIT_USE_INTERNAL_SHELL=0
+# env var.
+use_lit_shell = True
+lit_shell_env = os.environ.get("LIT_USE_INTERNAL_SHELL")
+if lit_shell_env:
+    use_lit_shell = lit.util.pythonize_bool(lit_shell_env)
+
 # testFormat: The test format to use to interpret tests.
 #
 # For now we require '&&' between commands, until they get globally killed and the test runner updated.
-config.test_format = lit.formats.ShTest(not llvm_config.use_lit_shell)
+config.test_format = lit.formats.ShTest(execute_external=not use_lit_shell)
 
 # suffixes: A list of file extensions to treat as test files.
 config.suffixes = [".ll", ".s", ".test", ".yaml", ".objtxt"]

llvm/include/llvm/CodeGen/GlobalISel/LegalizerHelper.h

@@ -364,6 +364,43 @@ class LegalizerHelper {
                                                       LLT HalfTy,
                                                       LLT ShiftAmtTy);
 
+  /// Multi-way shift legalization: directly split wide shifts into target-sized
+  /// parts in a single step, avoiding recursive binary splitting.
+  LLVM_ABI LegalizeResult narrowScalarShiftMultiway(MachineInstr &MI,
+                                                    LLT TargetTy);
+
+  /// Optimized path for constant shift amounts using static indexing.
+  /// Directly calculates which source parts contribute to each output part
+  /// without generating runtime select chains.
+  LLVM_ABI LegalizeResult narrowScalarShiftByConstantMultiway(MachineInstr &MI,
+                                                              const APInt &Amt,
+                                                              LLT TargetTy,
+                                                              LLT ShiftAmtTy);
+
+  struct ShiftParams {
+    Register WordShift;   // Number of complete words to shift
+    Register BitShift;    // Number of bits to shift within words
+    Register InvBitShift; // Complement bit shift (TargetBits - BitShift)
+    Register Zero;        // Zero constant for SHL/LSHR fill
+    Register SignBit;     // Sign extension value for ASHR fill
+  };
+
+  /// Generates a single output part for constant shifts using direct indexing.
+  /// Calculates which source parts contribute and how they're combined.
+  LLVM_ABI Register buildConstantShiftPart(unsigned Opcode, unsigned PartIdx,
+                                           unsigned NumParts,
+                                           ArrayRef<Register> SrcParts,
+                                           const ShiftParams &Params,
+                                           LLT TargetTy, LLT ShiftAmtTy);
+
+  /// Generates a shift part with carry for variable shifts.
+  /// Combines main operand shifted by BitShift with carry bits from adjacent
+  /// operand.
+  LLVM_ABI Register buildVariableShiftPart(unsigned Opcode,
+                                           Register MainOperand,
+                                           Register ShiftAmt, LLT TargetTy,
+                                           Register CarryOperand = Register());
+
   LLVM_ABI LegalizeResult fewerElementsVectorReductions(MachineInstr &MI,
                                                         unsigned TypeIdx,
                                                         LLT NarrowTy);