Refactor Expr(:simdloop) to Expr(:loopinfo, ...)

- `Expr(:loopinfo, Symbol("julia.simdloop"))` replaces
  `Expr(:simdloop, false)`
- `Expr(:loopinfo, Symbol("julia.simdloop"), Symbol("julia.ivdep"))` replaces
  `Expr(:simdloop, true)`

While currently not directly exposed users can now pass other
[loopinfo](https://llvm.org/docs/LangRef.html#llvm-loop) metadata to
LLVM.

base/compiler/abstractinterpretation.jl

@@ -1154,7 +1154,7 @@ function typeinf_local(frame::InferenceState)
  if isa(fname, Slot)
  changes = StateUpdate(fname, VarState(Any, false), changes)
  end
- elseif hd === :inbounds || hd === :meta || hd === :simdloop
+ elseif hd === :inbounds || hd === :meta || hd === :loopinfo
  else
  t = abstract_eval(stmt, changes, frame)
  t === Bottom && break

base/compiler/optimize.jl

@@ -155,7 +155,7 @@ function stmt_affects_purity(@nospecialize(stmt), ir)
  return !(t ⊑ Bool)
  end
  if isa(stmt, Expr)
- return stmt.head != :simdloop && stmt.head != :enter
+ return stmt.head != :loopinfo && stmt.head != :enter
  end
  return true
 end

base/compiler/ssair/queries.jl

@@ -50,7 +50,7 @@ function stmt_effect_free(@nospecialize(stmt), @nospecialize(rt), src, sptypes::
  elseif head === :isdefined || head === :the_exception || head === :copyast || head === :inbounds || head === :boundscheck
  return true
  else
- # e.g. :simdloop
+ # e.g. :loopinfo
  return false
  end
  end

base/compiler/utilities.jl

@@ -59,7 +59,7 @@ end
 
 # Meta expression head, these generally can't be deleted even when they are
 # in a dead branch but can be ignored when analyzing uses/liveness.
-is_meta_expr_head(head::Symbol) = (head === :inbounds || head === :boundscheck || head === :meta || head === :simdloop)
+is_meta_expr_head(head::Symbol) = (head === :inbounds || head === :boundscheck || head === :meta || head === :loopinfo)
 
 sym_isless(a::Symbol, b::Symbol) = ccall(:strcmp, Int32, (Ptr{UInt8}, Ptr{UInt8}), a, b) < 0
 

base/compiler/validation.jl

@@ -26,7 +26,7 @@ const VALID_EXPR_HEADS = IdDict{Any,Any}(
  :foreigncall => 3:typemax(Int),
  :cfunction => 5:5,
  :isdefined => 1:1,
- :simdloop => 1:1,
+ :loopinfo => 0:typemax(Int),
  :gc_preserve_begin => 0:typemax(Int),
  :gc_preserve_end => 0:typemax(Int),
  :thunk => 1:1,
@@ -143,7 +143,7 @@ function validate_code!(errors::Vector{>:InvalidCodeError}, c::CodeInfo, is_top_
  head === :inbounds || head === :foreigncall || head === :cfunction ||
  head === :const || head === :enter || head === :leave || head == :pop_exception ||
  head === :method || head === :global || head === :static_parameter ||
- head === :new || head === :splatnew || head === :thunk || head === :simdloop ||
+ head === :new || head === :splatnew || head === :thunk || head === :loopinfo ||
  head === :throw_undef_if_not || head === :unreachable
  validate_val!(x)
  else

base/meta.jl

@@ -293,6 +293,6 @@ end
 
 _instantiate_type_in_env(x, spsig, spvals) = ccall(:jl_instantiate_type_in_env, Any, (Any, Any, Ptr{Any}), x, spsig, spvals)
 
-is_meta_expr_head(head::Symbol) = (head === :inbounds || head === :boundscheck || head === :meta || head === :simdloop)
+is_meta_expr_head(head::Symbol) = (head === :inbounds || head === :boundscheck || head === :meta || head === :loopinfo)
 
 end # module

base/simdloop.jl

@@ -37,7 +37,7 @@ check_body!(x::QuoteNode) = check_body!(x.value)
 check_body!(x) = true
 
 # @simd splits a for loop into two loops: an outer scalar loop and
-# an inner loop marked with :simdloop. The simd_... functions define
+# an inner loop marked with :loopinfo. The simd_... functions define
 # the splitting.
 # Custom iterators that do not support random access cannot support
 # vectorization. In order to be compatible with `@simd` annotated loops,
@@ -76,7 +76,7 @@ function compile(x, ivdep)
  local $var = Base.simd_index($r,$j,$i)
  $(x.args[2]) # Body of loop
  $i += 1
- $(Expr(:simdloop, ivdep)) # Mark loop as SIMD loop
+ $(Expr(:loopinfo, Symbol("julia.simdloop"), ivdep)) # Mark loop as SIMD loop
  end
  end
  end
@@ -125,12 +125,12 @@ either case, your inner loop should have the following properties to allow vecto
 * No iteration ever waits on a previous iteration to make forward progress.
 """
 macro simd(forloop)
- esc(compile(forloop, false))
+ esc(compile(forloop, nothing))
 end
 
 macro simd(ivdep, forloop)
  if ivdep == :ivdep
- esc(compile(forloop, true))
+ esc(compile(forloop, Symbol("julia.ivdep")))
  else
  throw(SimdError("Only ivdep is valid as the first argument to @simd"))
  end

doc/src/devdocs/ast.md

@@ -452,9 +452,10 @@ These symbols appear in the `head` field of [`Expr`](@ref)s in lowered form.
  Has the value `false` if inlined into a section of code marked with `@inbounds`,
  otherwise has the value `true`.
 
- * `simdloop`
+ * `loopinfo`
 
- Marks the end of the inner loop of a `@simd` expression.
+ Marks the end of the a loop. Contains metadata that is passed to `LowerSimdLoop` to either mark
+ the inner loop of `@simd` expression, or to propagate information to LLVM loop passes.
 
  * `copyast`
 

src/ast.c

@@ -49,7 +49,7 @@ jl_sym_t *global_sym; jl_sym_t *list_sym;
 jl_sym_t *dot_sym; jl_sym_t *newvar_sym;
 jl_sym_t *boundscheck_sym; jl_sym_t *inbounds_sym;
 jl_sym_t *copyast_sym; jl_sym_t *cfunction_sym;
-jl_sym_t *pure_sym; jl_sym_t *simdloop_sym;
+jl_sym_t *pure_sym; jl_sym_t *loopinfo_sym;
 jl_sym_t *meta_sym; jl_sym_t *inert_sym;
 jl_sym_t *polly_sym; jl_sym_t *unused_sym;
 jl_sym_t *static_parameter_sym; jl_sym_t *inline_sym;
@@ -341,7 +341,7 @@ void jl_init_frontend(void)
  inbounds_sym = jl_symbol("inbounds");
  newvar_sym = jl_symbol("newvar");
  copyast_sym = jl_symbol("copyast");
- simdloop_sym = jl_symbol("simdloop");
+ loopinfo_sym = jl_symbol("loopinfo");
  pure_sym = jl_symbol("pure");
  meta_sym = jl_symbol("meta");
  list_sym = jl_symbol("list");

src/codegen.cpp

@@ -86,9 +86,6 @@
 #include <llvm/ExecutionEngine/ExecutionEngine.h>
 
 using namespace llvm;
-namespace llvm {
- extern bool annotateSimdLoop(BasicBlock *latch);
-}
 
 #if defined(_OS_WINDOWS_) && !defined(NOMINMAX)
 #define NOMINMAX
@@ -296,8 +293,7 @@ static Function *jlegal_func;
 static Function *jl_alloc_obj_func;
 static Function *jl_newbits_func;
 static Function *jl_typeof_func;
-static Function *jl_simdloop_marker_func;
-static Function *jl_simdivdep_marker_func;
+static Function *jl_loopinfo_marker_func;
 static Function *jl_write_barrier_func;
 static Function *jlisa_func;
 static Function *jlsubtype_func;
@@ -4100,14 +4096,43 @@ static jl_cgval_t emit_expr(jl_codectx_t &ctx, jl_value_t *expr, ssize_t ssaval)
  ctx.builder.CreateCall(prepare_call(jlcopyast_func),
  maybe_decay_untracked(boxed(ctx, ast))), true, jl_expr_type);
  }
- else if (head == simdloop_sym) {
- jl_value_t *ivdep = args[0];
- assert(jl_expr_nargs(ex) == 1 && jl_is_bool(ivdep));
- if (ivdep == jl_false) {
- ctx.builder.CreateCall(prepare_call(jl_simdloop_marker_func));
- } else {
- ctx.builder.CreateCall(prepare_call(jl_simdivdep_marker_func));
+ else if (head == loopinfo_sym) {
+ // parse Expr(:loopinfo, "julia.simdloop", ("llvm.loop.vectorize.width", 4))
+ SmallVector<Metadata *, 8> MDs;
+ for (int i = 0, ie = jl_expr_nargs(ex); i < ie; ++i) {
+ jl_value_t *arg = args[i];
+ Metadata *MD;
+ if (arg == jl_nothing)
+ continue;
+ if (jl_is_symbol(arg)) {
+ MD = MDString::get(jl_LLVMContext, jl_symbol_name((jl_sym_t*)arg));
+ } else if (jl_is_tuple(arg)) {
+ // TODO: are there loopinfo with more than one field?
+ if (jl_nfields(arg) != 2)
+ jl_error("loopinfo: only accept 2-arg tuple");
+ jl_value_t* name = jl_fieldref(arg, 0);
+ jl_value_t* value = jl_fieldref(arg, 1);
+ if (!jl_is_symbol(name))
+ jl_error("loopinfo: name needs to be a symbol");
+ Metadata *MDVal;
+ if(jl_is_bool(value))
+ MDVal = ConstantAsMetadata::get(ConstantInt::get(T_int1, jl_unbox_bool(value)));
+ if(jl_is_long(value))
+ MDVal = ConstantAsMetadata::get(ConstantInt::get(T_int64, jl_unbox_long(value)));
+ if(!MDVal)
+ jl_error("loopinfo: value can only be a bool or a long");
+ MD = MDNode::get(jl_LLVMContext,
+ { MDString::get(jl_LLVMContext, jl_symbol_name((jl_sym_t*)name)), MDVal });
+ }
+ if (MD)
+ MDs.push_back(MD);
+ else
+ jl_error("loopinfo: argument needs to be either a symbol or a tuple of type (Symbol, Union{Int, Bool}");
  }
+
+ MDNode* MD = MDNode::get(jl_LLVMContext, MDs);
+ CallInst *I = ctx.builder.CreateCall(prepare_call(jl_loopinfo_marker_func));
+ I->setMetadata("julia.loopinfo", MD);
  return jl_cgval_t();
  }
  else if (head == goto_ifnot_sym) {
@@ -7356,19 +7381,12 @@ static void init_julia_llvm_env(Module *m)
  add_return_attr(jl_newbits_func, Attribute::NonNull);
  add_named_global(jl_newbits_func, (void*)jl_new_bits);
 
- jl_simdloop_marker_func = Function::Create(FunctionType::get(T_void, {}, false),
- Function::ExternalLinkage,
- "julia.simdloop_marker");
- jl_simdloop_marker_func->addFnAttr(Attribute::NoUnwind);
- jl_simdloop_marker_func->addFnAttr(Attribute::NoRecurse);
- jl_simdloop_marker_func->addFnAttr(Attribute::InaccessibleMemOnly);
-
- jl_simdivdep_marker_func = Function::Create(FunctionType::get(T_void, {}, false),
+ jl_loopinfo_marker_func = Function::Create(FunctionType::get(T_void, {}, false),
  Function::ExternalLinkage,
- "julia.simdivdep_marker");
- jl_simdivdep_marker_func->addFnAttr(Attribute::NoUnwind);
- jl_simdivdep_marker_func->addFnAttr(Attribute::NoRecurse);
- jl_simdivdep_marker_func->addFnAttr(Attribute::InaccessibleMemOnly);
+ "julia.loopinfo_marker");
+ jl_loopinfo_marker_func->addFnAttr(Attribute::NoUnwind);
+ jl_loopinfo_marker_func->addFnAttr(Attribute::NoRecurse);
+ jl_loopinfo_marker_func->addFnAttr(Attribute::InaccessibleMemOnly);
 
  jl_typeof_func = Function::Create(FunctionType::get(T_prjlvalue, {T_prjlvalue}, false),
  Function::ExternalLinkage,

src/interpreter.c

@@ -498,7 +498,7 @@ SECT_INTERP static jl_value_t *eval_value(jl_value_t *e, interpreter_state *s)
  else if (head == boundscheck_sym) {
  return jl_true;
  }
- else if (head == meta_sym || head == inbounds_sym || head == simdloop_sym) {
+ else if (head == meta_sym || head == inbounds_sym || head == loopinfo_sym) {
  return jl_nothing;
  }
  else if (head == gc_preserve_begin_sym || head == gc_preserve_end_sym) {

src/jitlayers.cpp

@@ -121,8 +121,8 @@ void addOptimizationPasses(legacy::PassManagerBase *PM, int opt_level,
  PM->add(createGCInvariantVerifierPass(false));
  PM->add(createLateLowerGCFramePass());
  PM->add(createLowerPTLSPass(dump_native));
- PM->add(createLowerSimdLoopPass()); // Annotate loop marked with "simdloop" as LLVM parallel loop
  }
+ PM->add(createLowerSimdLoopPass()); // Annotate loop marked with "loopinfo" as LLVM parallel loop
  if (dump_native)
  PM->add(createMultiVersioningPass());
  return;
@@ -180,7 +180,7 @@ void addOptimizationPasses(legacy::PassManagerBase *PM, int opt_level,
  PM->add(polly::createCodegenCleanupPass());
 #endif
  // LoopRotate strips metadata from terminator, so run LowerSIMD afterwards
- PM->add(createLowerSimdLoopPass()); // Annotate loop marked with "simdloop" as LLVM parallel loop
+ PM->add(createLowerSimdLoopPass()); // Annotate loop marked with "loopinfo" as LLVM parallel loop
  PM->add(createLICMPass()); // Hoist loop invariants
  PM->add(createLoopUnswitchPass()); // Unswitch loops.
  // Subsequent passes not stripping metadata from terminator
@@ -236,8 +236,8 @@ void addOptimizationPasses(legacy::PassManagerBase *PM, int opt_level,
  PM->add(createLowerPTLSPass(dump_native));
  // Clean up write barrier and ptls lowering
  PM->add(createCFGSimplificationPass());
- PM->add(createCombineMulAddPass());
  }
+ PM->add(createCombineMulAddPass());
 }
 
 extern "C" JL_DLLEXPORT

src/julia-syntax.scm

@@ -2951,7 +2951,7 @@ f(x) = yt(x)
 
 (define lambda-opt-ignored-exprs
  (Set '(quote top core line inert local local-def unnecessary copyast
- meta inbounds boundscheck simdloop decl aliasscope popaliasscope
+ meta inbounds boundscheck loopinfo decl aliasscope popaliasscope
  struct_type abstract_type primitive_type thunk with-static-parameters
  implicit-global global globalref outerref const-if-global
  const null ssavalue isdefined toplevel module lambda error
@@ -3971,7 +3971,7 @@ f(x) = yt(x)
  s))
 
  ;; metadata expressions
- ((line meta inbounds simdloop gc_preserve_end aliasscope popaliasscope)
+ ((line meta inbounds loopinfo gc_preserve_end aliasscope popaliasscope)
  (let ((have-ret? (and (pair? code) (pair? (car code)) (eq? (caar code) 'return))))
  (cond ((eq? (car e) 'line)
  (set! current-loc e)

src/julia_internal.h

@@ -1003,7 +1003,7 @@ extern jl_sym_t *dot_sym; extern jl_sym_t *newvar_sym;
 extern jl_sym_t *boundscheck_sym; extern jl_sym_t *inbounds_sym;
 extern jl_sym_t *aliasscope_sym; extern jl_sym_t *popaliasscope_sym;
 extern jl_sym_t *copyast_sym; extern jl_sym_t *cfunction_sym;
-extern jl_sym_t *pure_sym; extern jl_sym_t *simdloop_sym;
+extern jl_sym_t *pure_sym; extern jl_sym_t *loopinfo_sym;
 extern jl_sym_t *meta_sym; extern jl_sym_t *inert_sym;
 extern jl_sym_t *polly_sym; extern jl_sym_t *unused_sym;
 extern jl_sym_t *static_parameter_sym; extern jl_sym_t *inline_sym;