complete ppc64le c-abi (sans vector types extension)

future work: consider adding `align 8` to byval to match clang

src/abi_ppc64le.cpp

@@ -42,46 +42,67 @@
 typedef bool AbiState;
 AbiState default_abi_state = 0;
 
-static bool isHFA(jl_datatype_t *ty)
+// count the homogeneous floating agregate size (saturating at max count of 8)
+static unsigned isHFA(jl_datatype_t *ty, jl_datatype_t **ty0)
 {
  size_t i, l = ty->nfields;
- jl_value_t *fld0 = jl_field_type(ty, 0);
- if (l > 8)
- return false;
- if (fld0 != (jl_value_t*)jl_float64_type && fld0 != (jl_value_t*)jl_float32_type)
- return false;
- for (i = 1; i < l; i++) {
+ if (l == 0) {
+ if (*ty0 == NULL) {
+ if (ty == jl_float64_type || ty == jl_float32_type)
+ *ty0 = ty;
+ }
+ return ty == *ty0 ? 1 : 9;
+ }
+ int n = 0;
+ for (i = 0; i < l; i++) {
  jl_value_t *fld = jl_field_type(ty, i);
- if (fld != fld0)
- return false;
+ if (!jl_is_datatype(fld))
+ return 9;
+ n += isHFA((jl_datatype_t*)fld, ty0);
+ if (n > 8)
+ return 9;
  }
- return true;
+ return n;
 }
 
 bool use_sret(AbiState *state, jl_value_t *ty)
 {
  // Assume jl_is_datatype(ty) && !jl_is_abstracttype(ty)
  jl_datatype_t *dt = (jl_datatype_t*)ty;
- if (dt->size > 16 && !isHFA(dt))
+ jl_datatype_t *ty0 = NULL;
+ if (dt->size > 16 && isHFA(dt, &ty0) > 8)
  return true;
  return false;
 }
 
 void needPassByRef(AbiState *state, jl_value_t *ty, bool *byRef, bool *inReg)
 {
- *byRef = false;
+ if (!jl_is_datatype(ty) || jl_is_abstracttype(ty) || jl_is_cpointer_type(ty) || jl_is_array_type(ty))
+ return;
+ size_t size = jl_datatype_size(ty);
+ if (size > 64)
+ *byRef = true;
 }
 
 Type *preferred_llvm_type(jl_value_t *ty, bool isret)
 {
  // Arguments are either scalar or passed by value
- if (!jl_is_datatype(ty) || jl_is_abstracttype(ty))
+ if (!jl_is_datatype(ty) || jl_is_abstracttype(ty) || jl_is_cpointer_type(ty) || jl_is_array_type(ty))
  return NULL;
  jl_datatype_t *dt = (jl_datatype_t*)ty;
- // rewrite integer sized (non-HFA) struct to the corresponding integer
- if (!dt->nfields || (isret ? use_sret(NULL, ty) : false) || isHFA(dt))
+ size_t size = dt->size;
+ // don't need to change bitstypes
+ if (!dt->nfields)
  return NULL;
- return Type::getIntNTy(jl_LLVMContext, dt->size * 8);
+ // legalize this into [n x f32/f64]
+ jl_datatype_t *ty0 = NULL;
+ int hfa = isHFA(dt, &ty0);
+ if (hfa <= 8)
+ return ArrayType::get(ty0 == jl_float32_type ? T_float32 : T_float64, hfa);
+ // rewrite integer-sized (non-HFA) struct to an array of i64
+ if (size > 8)
+ return ArrayType::get(T_int64, (size + 7) / 8);
+ return Type::getIntNTy(jl_LLVMContext, size * 8);
 }
 
 bool need_private_copy(jl_value_t *ty, bool byRef)

src/abi_win32.cpp

@@ -67,7 +67,7 @@ Type *preferred_llvm_type(jl_value_t *ty, bool isret)
  return NULL;
  jl_datatype_t *dt = (jl_datatype_t*)ty;
  // rewrite integer sized (non-sret) struct to the corresponding integer
- if (!dt->nfields || use_sret(NULL, ty))
+ if (!dt->nfields)
  return NULL;
  return Type::getIntNTy(jl_LLVMContext, dt->size * 8);
 }

src/ccall.cpp

@@ -876,7 +876,6 @@ static std::string generate_func_sig(
  size_t nargt = jl_svec_len(tt);
  assert(rt && !jl_is_abstract_ref_type(rt));
 
- AttrBuilder retattrs;
  std::vector<AttrBuilder> paramattrs;
  AbiState abi = default_abi_state;
  sret = 0;
@@ -885,7 +884,7 @@ static std::string generate_func_sig(
  *prt = *lrt = T_void;
  }
  else {
- *prt = preferred_llvm_type(rt, true);
+ *prt = sret ? NULL : preferred_llvm_type(rt, true);
  if (*prt == NULL)
  *prt = *lrt;
 
@@ -895,6 +894,7 @@ static std::string generate_func_sig(
 #if !defined(_OS_WINDOWS_) || defined(LLVM35) // llvm used to use the old mingw ABI, skipping this marking works around that difference
  paramattrs[0].addAttribute(Attribute::StructRet);
 #endif
+ paramattrs[0].addAttribute(Attribute::NoAlias);
  fargt_sig.push_back(PointerType::get(*prt, 0));
  sret = 1;
  }
@@ -953,14 +953,8 @@ static std::string generate_func_sig(
  needPassByRef(&abi, tti, &byRef, &inReg);
  }
 
- Type *pat = preferred_llvm_type(tti, false);
- if (pat != NULL) {
- assert(!byRef); // it is an error for an ABI to specify a preferred type for a pointer arg
- }
- else if (byRef) {
- pat = PointerType::get(t, 0);
- }
- else {
+ Type *pat = byRef ? PointerType::get(t, 0) : preferred_llvm_type(tti, false);
+ if (pat == NULL) {
  pat = t;
  }
 
@@ -994,10 +988,6 @@ static std::string generate_func_sig(
  } while (current_isVa && i < nargs); // if is this is the vararg, loop to the end
  }
 
- if (retattrs.hasAttributes()) {
- attributes = AttributeSet::get(jl_LLVMContext, AttributeSet::ReturnIndex, retattrs);
- }
-
  for (i = 0; i < nargs + sret; ++i) {
  if (paramattrs[i].hasAttributes()) {
  attributes = attributes.addAttributes(jl_LLVMContext, i + 1,

src/codegen.cpp

@@ -4126,8 +4126,10 @@ static std::unique_ptr<Module> emit_function(jl_lambda_info_t *lam, jl_llvm_func
  f = Function::Create(FunctionType::get(rt, fsig, false),
  GlobalVariable::ExternalLinkage,
  funcName.str(), M);
- if (ctx.sret)
+ if (ctx.sret) {
  f->addAttribute(1, Attribute::StructRet);
+ f->addAttribute(1, Attribute::NoAlias);
+ }
  addComdat(f);
 #ifdef LLVM37
  f->addFnAttr("no-frame-pointer-elim", "true");