ee86f96ba1
Stop generating `alloca`s & `memcmp` for simple short array equality Example: ```rust pub fn demo(x: [u16; 6], y: [u16; 6]) -> bool { x == y } ``` Before: ```llvm define zeroext i1 `@_ZN10playground4demo17h48537f7eac23948fE(i96` %0, i96 %1) unnamed_addr #0 { start: %y = alloca [6 x i16], align 8 %x = alloca [6 x i16], align 8 %.0..sroa_cast = bitcast [6 x i16]* %x to i96* store i96 %0, i96* %.0..sroa_cast, align 8 %.0..sroa_cast3 = bitcast [6 x i16]* %y to i96* store i96 %1, i96* %.0..sroa_cast3, align 8 %_11.i.i.i = bitcast [6 x i16]* %x to i8* %_14.i.i.i = bitcast [6 x i16]* %y to i8* %bcmp.i.i.i = call i32 `@bcmp(i8*` nonnull dereferenceable(12) %_11.i.i.i, i8* nonnull dereferenceable(12) %_14.i.i.i, i64 12) #2, !alias.scope !2 %2 = icmp eq i32 %bcmp.i.i.i, 0 ret i1 %2 } ``` ```x86 playground::demo: # `@playground::demo` sub rsp, 32 mov qword ptr [rsp], rdi mov dword ptr [rsp + 8], esi mov qword ptr [rsp + 16], rdx mov dword ptr [rsp + 24], ecx xor rdi, rdx xor esi, ecx or rsi, rdi sete al add rsp, 32 ret ``` After: ```llvm define zeroext i1 `@_ZN4mini4demo17h7a8994aaa314c981E(i96` %0, i96 %1) unnamed_addr #0 { start: %2 = icmp eq i96 %0, %1 ret i1 %2 } ``` ```x86 _ZN4mini4demo17h7a8994aaa314c981E: xor rcx, r8 xor edx, r9d or rdx, rcx sete al ret ``` |
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rustc | ||
rustc_apfloat | ||
rustc_arena | ||
rustc_ast | ||
rustc_ast_lowering | ||
rustc_ast_passes | ||
rustc_ast_pretty | ||
rustc_attr | ||
rustc_builtin_macros | ||
rustc_codegen_cranelift | ||
rustc_codegen_llvm | ||
rustc_codegen_ssa | ||
rustc_data_structures | ||
rustc_driver | ||
rustc_error_codes | ||
rustc_errors | ||
rustc_expand | ||
rustc_feature | ||
rustc_fs_util | ||
rustc_graphviz | ||
rustc_hir | ||
rustc_hir_pretty | ||
rustc_incremental | ||
rustc_index | ||
rustc_infer | ||
rustc_interface | ||
rustc_lexer | ||
rustc_lint | ||
rustc_lint_defs | ||
rustc_llvm | ||
rustc_macros | ||
rustc_metadata | ||
rustc_middle | ||
rustc_mir | ||
rustc_mir_build | ||
rustc_parse | ||
rustc_parse_format | ||
rustc_passes | ||
rustc_plugin_impl | ||
rustc_privacy | ||
rustc_query_impl | ||
rustc_query_system | ||
rustc_resolve | ||
rustc_save_analysis | ||
rustc_serialize | ||
rustc_session | ||
rustc_span | ||
rustc_symbol_mangling | ||
rustc_target | ||
rustc_trait_selection | ||
rustc_traits | ||
rustc_ty_utils | ||
rustc_type_ir | ||
rustc_typeck |