From d5968086fe357aa5cf678327295677dba5102fc8 Mon Sep 17 00:00:00 2001
From: Andrew Kelley <superjoe30@gmail.com>
Date: Sun, 2 Sep 2018 21:08:59 -0400
Subject: use the sret attribute at the callsite when appropriate

Thanks to Shawn Landden for the original pull request.

closes #1450
---
 src/codegen.cpp | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

(limited to 'src/codegen.cpp')

diff --git a/src/codegen.cpp b/src/codegen.cpp
index f25ecd8e08..388a1a371f 100644
--- a/src/codegen.cpp
+++ b/src/codegen.cpp
@@ -3101,6 +3101,12 @@ static void gen_set_stack_pointer(CodeGen *g, LLVMValueRef aligned_end_addr) {
     LLVMBuildCall(g->builder, write_register_fn_val, params, 2, "");
 }
 
+static void set_call_instr_sret(CodeGen *g, LLVMValueRef call_instr) {
+    unsigned attr_kind_id = LLVMGetEnumAttributeKindForName("sret", 4);
+    LLVMAttributeRef sret_attr = LLVMCreateEnumAttribute(LLVMGetGlobalContext(), attr_kind_id, 1);
+    LLVMAddCallSiteAttribute(call_instr, 1, sret_attr);
+}
+
 static LLVMValueRef ir_render_call(CodeGen *g, IrExecutable *executable, IrInstructionCall *instruction) {
     LLVMValueRef fn_val;
     TypeTableEntry *fn_type;
@@ -3196,6 +3202,7 @@ static LLVMValueRef ir_render_call(CodeGen *g, IrExecutable *executable, IrInstr
     } else if (!ret_has_bits) {
         return nullptr;
     } else if (first_arg_ret) {
+        set_call_instr_sret(g, result);
         return instruction->tmp_ptr;
     } else if (handle_is_ptr(src_return_type)) {
         auto store_instr = LLVMBuildStore(g->builder, result, instruction->tmp_ptr);
@@ -4662,8 +4669,9 @@ static LLVMValueRef get_coro_alloc_helper_fn_val(CodeGen *g, LLVMTypeRef alloc_f
     args.append(allocator_val);
     args.append(coro_size);
     args.append(alignment_val);
-    ZigLLVMBuildCall(g->builder, alloc_fn_val, args.items, args.length,
+    LLVMValueRef call_instruction = ZigLLVMBuildCall(g->builder, alloc_fn_val, args.items, args.length,
             get_llvm_cc(g, CallingConventionUnspecified), ZigLLVM_FnInlineAuto, "");
+    set_call_instr_sret(g, call_instruction);
     LLVMValueRef err_val_ptr = LLVMBuildStructGEP(g->builder, sret_ptr, err_union_err_index, "");
     LLVMValueRef err_val = LLVMBuildLoad(g->builder, err_val_ptr, "");
     LLVMBuildStore(g->builder, err_val, err_code_ptr);
-- 
cgit v1.2.3


From 95636c7e5ff6ad0eeb768a2a0a1d7533b5872e20 Mon Sep 17 00:00:00 2001
From: Andrew Kelley <superjoe30@gmail.com>
Date: Mon, 3 Sep 2018 00:04:12 -0400
Subject: ability to @ptrCast to *void

fixes #960
---
 src/codegen.cpp     |  3 +++
 src/ir.cpp          | 10 ++++++++--
 test/cases/cast.zig |  6 ++++++
 3 files changed, 17 insertions(+), 2 deletions(-)

(limited to 'src/codegen.cpp')

diff --git a/src/codegen.cpp b/src/codegen.cpp
index 388a1a371f..298e89579f 100644
--- a/src/codegen.cpp
+++ b/src/codegen.cpp
@@ -2655,6 +2655,9 @@ static LLVMValueRef ir_render_ptr_cast(CodeGen *g, IrExecutable *executable,
         IrInstructionPtrCast *instruction)
 {
     TypeTableEntry *wanted_type = instruction->base.value.type;
+    if (!type_has_bits(wanted_type)) {
+        return nullptr;
+    }
     LLVMValueRef ptr = ir_llvm_value(g, instruction->ptr);
     return LLVMBuildBitCast(g->builder, ptr, wanted_type->type_ref, "");
 }
diff --git a/src/ir.cpp b/src/ir.cpp
index 4e64b3e002..2c3fadfc2d 100644
--- a/src/ir.cpp
+++ b/src/ir.cpp
@@ -19757,6 +19757,8 @@ static IrInstruction *ir_align_cast(IrAnalyze *ira, IrInstruction *target, uint3
 }
 
 static TypeTableEntry *ir_analyze_instruction_ptr_cast(IrAnalyze *ira, IrInstructionPtrCast *instruction) {
+    Error err;
+
     IrInstruction *dest_type_value = instruction->dest_type->other;
     TypeTableEntry *dest_type = ir_resolve_type(ira, dest_type_value);
     if (type_is_invalid(dest_type))
@@ -19810,9 +19812,13 @@ static TypeTableEntry *ir_analyze_instruction_ptr_cast(IrAnalyze *ira, IrInstruc
             instruction->base.source_node, nullptr, ptr);
     casted_ptr->value.type = dest_type;
 
-    // keep the bigger alignment, it can only help
+    // Keep the bigger alignment, it can only help-
+    // unless the target is zero bits.
+    if ((err = type_ensure_zero_bits_known(ira->codegen, dest_type)))
+        return ira->codegen->builtin_types.entry_invalid;
+
     IrInstruction *result;
-    if (src_align_bytes > dest_align_bytes) {
+    if (src_align_bytes > dest_align_bytes && type_has_bits(dest_type)) {
         result = ir_align_cast(ira, casted_ptr, src_align_bytes, false);
         if (type_is_invalid(result->value.type))
             return ira->codegen->builtin_types.entry_invalid;
diff --git a/test/cases/cast.zig b/test/cases/cast.zig
index cc5e4b4394..2b455ccc43 100644
--- a/test/cases/cast.zig
+++ b/test/cases/cast.zig
@@ -519,3 +519,9 @@ fn incrementVoidPtrArray(array: ?*c_void, len: usize) void {
         @ptrCast([*]u8, array.?)[n] += 1;
     }
 }
+
+test "*usize to *void" {
+    var i = usize(0);
+    var v = @ptrCast(*void, &i);
+    v.* = {};
+}
-- 
cgit v1.2.3