From 19da68568e02e78c308afa0347eb9138ec23030c Mon Sep 17 00:00:00 2001
From: MerryMage <MerryMage@users.noreply.github.com>
Date: Wed, 17 Jan 2018 00:34:33 +0000
Subject: [PATCH] A64/translate/branch: bug: Read-after-write error in BLR

---
 src/backend_x64/a64_emit_x64.cpp           | 16 ++++++++++++----
 src/frontend/A64/translate/impl/branch.cpp |  5 ++++-
 src/frontend/ir/basic_block.cpp            |  4 ++--
 3 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/src/backend_x64/a64_emit_x64.cpp b/src/backend_x64/a64_emit_x64.cpp
index 0106c66e..dc569d8a 100644
--- a/src/backend_x64/a64_emit_x64.cpp
+++ b/src/backend_x64/a64_emit_x64.cpp
@@ -347,10 +347,18 @@ void A64EmitX64::EmitTerminalImpl(IR::Term::PopRSBHint, IR::LocationDescriptor i
 }
 
 void A64EmitX64::EmitTerminalImpl(IR::Term::If terminal, IR::LocationDescriptor initial_location) {
-    Xbyak::Label pass = EmitCond(terminal.if_);
-    EmitTerminal(terminal.else_, initial_location);
-    code->L(pass);
-    EmitTerminal(terminal.then_, initial_location);
+    switch (terminal.if_) {
+    case IR::Cond::AL:
+    case IR::Cond::NV:
+        EmitTerminal(terminal.then_, initial_location);
+        break;
+    default:
+        Xbyak::Label pass = EmitCond(terminal.if_);
+        EmitTerminal(terminal.else_, initial_location);
+        code->L(pass);
+        EmitTerminal(terminal.then_, initial_location);
+        break;
+    }
 }
 
 void A64EmitX64::EmitTerminalImpl(IR::Term::CheckBit terminal, IR::LocationDescriptor initial_location) {
diff --git a/src/frontend/A64/translate/impl/branch.cpp b/src/frontend/A64/translate/impl/branch.cpp
index 8592d9fe..0b549be2 100644
--- a/src/frontend/A64/translate/impl/branch.cpp
+++ b/src/frontend/A64/translate/impl/branch.cpp
@@ -39,10 +39,11 @@ bool TranslatorVisitor::BL(Imm<26> imm26) {
 }
 
 bool TranslatorVisitor::BLR(Reg Rn) {
+    auto target = X(64, Rn);
+
     X(64, Reg::R30, ir.Imm64(ir.PC() + 4));
     ir.PushRSB(ir.current_location.AdvancePC(4));
 
-    auto target = X(64, Rn);
     ir.SetPC(target);
     ir.SetTerm(IR::Term::ReturnToDispatch{});
     return false;
@@ -50,6 +51,7 @@ bool TranslatorVisitor::BLR(Reg Rn) {
 
 bool TranslatorVisitor::BR(Reg Rn) {
     auto target = X(64, Rn);
+
     ir.SetPC(target);
     ir.SetTerm(IR::Term::ReturnToDispatch{});
     return false;
@@ -57,6 +59,7 @@ bool TranslatorVisitor::BR(Reg Rn) {
 
 bool TranslatorVisitor::RET(Reg Rn) {
     auto target = X(64, Rn);
+
     ir.SetPC(target);
     ir.SetTerm(IR::Term::PopRSBHint{});
     return false;
diff --git a/src/frontend/ir/basic_block.cpp b/src/frontend/ir/basic_block.cpp
index c0a608b5..9d89021a 100644
--- a/src/frontend/ir/basic_block.cpp
+++ b/src/frontend/ir/basic_block.cpp
@@ -129,7 +129,7 @@ static std::string TerminalToString(const Terminal& terminal_variant) {
     }
     case 6: {
         auto terminal = boost::get<IR::Term::If>(terminal_variant);
-        return fmt::format("If{{{}, {}, {}}}", A32::CondToString(terminal.if_), TerminalToString(terminal.then_), TerminalToString(terminal.else_));
+        return fmt::format("If{{{}, {}, {}}}", A64::CondToString(terminal.if_), TerminalToString(terminal.then_), TerminalToString(terminal.else_));
     }
     case 7: {
         auto terminal = boost::get<IR::Term::CheckBit>(terminal_variant);
@@ -149,7 +149,7 @@ std::string DumpBlock(const IR::Block& block) {
 
     ret += fmt::format("Block: location={}\n", block.Location());
     ret += fmt::format("cycles={}", block.CycleCount());
-    ret += fmt::format(", entry_cond={}", A32::CondToString(block.GetCondition(), true));
+    ret += fmt::format(", entry_cond={}", A64::CondToString(block.GetCondition()));
     if (block.GetCondition() != Cond::AL) {
         ret += fmt::format(", cond_fail={}", block.ConditionFailedLocation());
     }