llvm-project

c005f737 - Fix "Cannot select" crash on bitcast between f64 and int vector types (#201509)

Fix "Cannot select" crash on bitcast between f64 and int vector types (#201509) All of i64, f64, v2i32, v4i16, v8i8 are assigned to the DoubleRegs register class (64-bit register pairs). A bitcast between any two of these types is a machine-level no-op (ie. the same physical register is reinterpreted with a different type). HexagonPatterns.td had NopCast_pat entries for all int-to-int bitcasts within DoubleRegs, and explicit patterns for f64 <-> i64, but was missing patterns for f64 <-> v2i32, f64 <-> v4i16, and f64 <-> v8i8. The same gap existed in IntRegs for f32 <-> v2i16 and f32 <-> v4i8. Without a tableGen pattern for "f64 = bitcast v2i32" node, the instruction selector crashed with: LLVM ERROR: Cannot select: t26: f64 = bitcast t6 t6: v2i32,ch = CopyFromReg t0, Register:v2i32 %2 Fix by adding the five missing NopCast_pat entries. Fixes: https://github.com/llvm/llvm-project/issues/195495