From 20e6c6520011ffd50ca851b537e84ab7fd995f4d Mon Sep 17 00:00:00 2001
From: Alexey Prokhin <alexey.prokhin@yandex.ru>
Date: Sat, 26 Feb 2011 13:04:09 +0300
Subject: [PATCH] To follow D ABI, swap real and imaginary parts of a complex
 return value on X86_64

TODO: should we disable this transformation for ldc1 in order to keep its ABI unchanged?
---
 gen/abi-generic.h  | 19 +++++++++++++++++++
 gen/abi-x86-64.cpp | 10 +++++++++-
 gen/abi.cpp        | 19 -------------------
 3 files changed, 28 insertions(+), 20 deletions(-)

diff --git a/gen/abi-generic.h b/gen/abi-generic.h
index a3ffa4a8..83a883c4 100644
--- a/gen/abi-generic.h
+++ b/gen/abi-generic.h
@@ -36,4 +36,23 @@ struct RemoveStructPadding : ABIRewrite {
     }
 };
 
+//////////////////////////////////////////////////////////////////////////////
+
+// simply swap of real/imag parts for proper x87 complex abi
+struct X87_complex_swap : ABIRewrite
+{
+    LLValue* get(Type*, DValue* v)
+    {
+        return DtoAggrPairSwap(v->getRVal());
+    }
+    LLValue* put(Type*, DValue* v)
+    {
+        return DtoAggrPairSwap(v->getRVal());
+    }
+    const LLType* type(Type*, const LLType* t)
+    {
+        return t;
+    }
+};
+
 #endif
diff --git a/gen/abi-x86-64.cpp b/gen/abi-x86-64.cpp
index e1ed8614..0839679b 100644
--- a/gen/abi-x86-64.cpp
+++ b/gen/abi-x86-64.cpp
@@ -497,6 +497,7 @@ struct RegCount {
 
 struct X86_64TargetABI : TargetABI {
     X86_64_C_struct_rewrite struct_rewrite;
+    X87_complex_swap swapComplex;
     RemoveStructPadding remove_padding;
     
     void newFunctionType(TypeFunction* tf) {
@@ -676,15 +677,22 @@ void X86_64TargetABI::fixup(IrFuncTyArg& arg) {
 
 void X86_64TargetABI::rewriteFunctionType(TypeFunction* tf) {
     IrFuncTy& fty = tf->fty;
+    Type* rt = fty.ret->type->toBasetype();
 
     if (tf->linkage == LINKd) {
         if (!fty.arg_sret) {
-            Type* rt = fty.ret->type->toBasetype();
             if (rt->ty == Tstruct && !fty.ret->byref)  {
                 Logger::println("x86-64 D ABI: Transforming return type");
                 fixup_D(*fty.ret);
             }
         }
+
+        // complex {re,im} -> {im,re}
+        if (rt->iscomplex())
+        {
+            Logger::println("Rewriting complex return value");
+            fty.ret->rewrite = &swapComplex;
+        }
         
 #if DMDV1
         if (fty.arg_this) {
diff --git a/gen/abi.cpp b/gen/abi.cpp
index ab0af4c9..50c3dd01 100644
--- a/gen/abi.cpp
+++ b/gen/abi.cpp
@@ -29,25 +29,6 @@ void ABIRewrite::getL(Type* dty, DValue* v, llvm::Value* lval)
 //////////////////////////////////////////////////////////////////////////////
 //////////////////////////////////////////////////////////////////////////////
 
-// simply swap of real/imag parts for proper x87 complex abi
-struct X87_complex_swap : ABIRewrite
-{
-    LLValue* get(Type*, DValue* v)
-    {
-        return DtoAggrPairSwap(v->getRVal());
-    }
-    LLValue* put(Type*, DValue* v)
-    {
-        return DtoAggrPairSwap(v->getRVal());
-    }
-    const LLType* type(Type*, const LLType* t)
-    {
-        return t;
-    }
-};
-
-//////////////////////////////////////////////////////////////////////////////
-
 struct X86_cfloat_rewrite : ABIRewrite
 {
     // i64 -> {float,float}