From 3220e0b61c127b60188a040b5f4679765e8f6f40 Mon Sep 17 00:00:00 2001
From: Koakuma <koachan@protonmail.com>
Date: Sat, 28 May 2022 09:05:57 +0700
Subject: [PATCH] stage2: sparc64: Proper handling of compare flags

---
 src/arch/sparc64/CodeGen.zig | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/arch/sparc64/CodeGen.zig b/src/arch/sparc64/CodeGen.zig
index f63995cf5c..a4c6635b4c 100644
--- a/src/arch/sparc64/CodeGen.zig
+++ b/src/arch/sparc64/CodeGen.zig
@@ -2029,6 +2029,7 @@ fn binOpImmediate(
     defer if (new_lhs_lock) |reg| self.register_manager.unlockReg(reg);
 
     const dest_reg = switch (mir_tag) {
+        .cmp => undefined, // cmp has no destination register
         else => if (metadata) |md| blk: {
             if (lhs_is_register and self.reuseOperand(
                 md.inst,
@@ -2148,6 +2149,7 @@ fn binOpRegister(
     defer if (new_rhs_lock) |reg| self.register_manager.unlockReg(reg);
 
     const dest_reg = switch (mir_tag) {
+        .cmp => undefined, // cmp has no destination register
         else => if (metadata) |md| blk: {
             if (lhs_is_register and self.reuseOperand(md.inst, md.lhs, 0, lhs)) {
                 break :blk lhs_reg;
@@ -3064,6 +3066,10 @@ fn processDeath(self: *Self, inst: Air.Inst.Index) void {
         .register => |reg| {
             self.register_manager.freeReg(reg);
         },
+        .register_with_overflow => |rwo| {
+            self.register_manager.freeReg(rwo.reg);
+            self.compare_flags_inst = null;
+        },
         .compare_flags_signed, .compare_flags_unsigned => {
             self.compare_flags_inst = null;
         },