[clang] [CIR] Extend VecShuffleOp verifier to catch invalid index (PR #143262)

[Amr Hesham via cfe-commits]

https://github.com/AmrDeveloper created https://github.com/llvm/llvm-project/pull/143262

Extend the verifier to catch index larger than the size of vector elements in VecShuffleOp

Issue https://github.com/llvm/llvm-project/issues/136487

>From 5f98861a88e544ec80bbaf5fe0ffb650c2d71e67 Mon Sep 17 00:00:00 2001
From: AmrDeveloper <amr96 at programmer.net>
Date: Sat, 7 Jun 2025 14:57:53 +0200
Subject: [PATCH] [CIR] Extend VecShuffleOp verifier to catch invalid index

---
 clang/lib/CIR/Dialect/IR/CIRDialect.cpp          |  8 ++++++++
 .../IR/invalid-vector-shuffle-wrong-index.cir    | 16 ++++++++++++++++
 2 files changed, 24 insertions(+)
 create mode 100644 clang/test/CIR/IR/invalid-vector-shuffle-wrong-index.cir

diff --git a/clang/lib/CIR/Dialect/IR/CIRDialect.cpp b/clang/lib/CIR/Dialect/IR/CIRDialect.cpp
index bfd3a0a62a8e7..b0678ee737a62 100644
--- a/clang/lib/CIR/Dialect/IR/CIRDialect.cpp
+++ b/clang/lib/CIR/Dialect/IR/CIRDialect.cpp
@@ -1599,6 +1599,14 @@ LogicalResult cir::VecShuffleOp::verify() {
                          << " and " << getResult().getType() << " don't match";
   }
 
+  const uint64_t maxValidIndex =
+      getVec1().getType().getSize() + getVec2().getType().getSize() - 1;
+  for (const auto &idxAttr : getIndices().getAsRange<cir::IntAttr>()) {
+    if (idxAttr.getUInt() > maxValidIndex)
+      return emitOpError() << ": index for __builtin_shufflevector must be "
+                              "less than the total number of vector elements";
+  }
+
   return success();
 }
 
diff --git a/clang/test/CIR/IR/invalid-vector-shuffle-wrong-index.cir b/clang/test/CIR/IR/invalid-vector-shuffle-wrong-index.cir
new file mode 100644
index 0000000000000..375b2d3dc563e
--- /dev/null
+++ b/clang/test/CIR/IR/invalid-vector-shuffle-wrong-index.cir
@@ -0,0 +1,16 @@
+// RUN: cir-opt %s -verify-diagnostics -split-input-file
+
+!s32i = !cir.int<s, 32>
+!s64i = !cir.int<s, 64>
+
+module  {
+  cir.func @fold_shuffle_vector_op_test() -> !cir.vector<4 x !s32i> {
+    %vec_1 = cir.const #cir.const_vector<[#cir.int<1> : !s32i, #cir.int<3> : !s32i, #cir.int<5> : !s32i, #cir.int<7> : !s32i]> : !cir.vector<4 x !s32i>
+    %vec_2 = cir.const #cir.const_vector<[#cir.int<2> : !s32i, #cir.int<4> : !s32i, #cir.int<6> : !s32i, #cir.int<8> : !s32i]> : !cir.vector<4 x !s32i>
+
+    // expected-error @below {{index for __builtin_shufflevector must be less than the total number of vector elements}}
+    %new_vec = cir.vec.shuffle(%vec_1, %vec_2 : !cir.vector<4 x !s32i>) [#cir.int<9> : !s64i, #cir.int<4> : !s64i,
+      #cir.int<1> : !s64i, #cir.int<5> : !s64i] : !cir.vector<4 x !s32i>
+    cir.return %new_vec : !cir.vector<4 x !s32i>
+  }
+}