From 6f09a7041ecf328f761df60fae007c800ee1e2ec Mon Sep 17 00:00:00 2001
From: mlugg <mlugg@mlugg.co.uk>
Date: Wed, 19 Apr 2023 01:58:39 +0100
Subject: [PATCH] Begin integrating new liveness analysis into remaining
 backends

---
 src/arch/aarch64/CodeGen.zig | 5 +++++
 src/arch/arm/CodeGen.zig     | 5 +++++
 src/arch/riscv64/CodeGen.zig | 5 +++++
 src/arch/sparc64/CodeGen.zig | 5 +++++
 src/arch/x86_64/CodeGen.zig  | 5 +++++
 src/codegen/spirv.zig        | 5 +++++
 6 files changed, 30 insertions(+)

diff --git a/src/arch/aarch64/CodeGen.zig b/src/arch/aarch64/CodeGen.zig
index f2116689e9..1acc11d7e8 100644
--- a/src/arch/aarch64/CodeGen.zig
+++ b/src/arch/aarch64/CodeGen.zig
@@ -655,6 +655,11 @@ fn genBody(self: *Self, body: []const Air.Inst.Index) InnerError!void {
     const air_tags = self.air.instructions.items(.tag);
 
     for (body) |inst| {
+        // TODO: remove now-redundant isUnused calls from AIR handler functions
+        if (self.liveness.isUnused(inst) and !self.air.mustLower(inst)) {
+            continue;
+        }
+
         const old_air_bookkeeping = self.air_bookkeeping;
         try self.ensureProcessDeathCapacity(Liveness.bpi);
 
diff --git a/src/arch/arm/CodeGen.zig b/src/arch/arm/CodeGen.zig
index 70144551d1..661e713b1c 100644
--- a/src/arch/arm/CodeGen.zig
+++ b/src/arch/arm/CodeGen.zig
@@ -639,6 +639,11 @@ fn genBody(self: *Self, body: []const Air.Inst.Index) InnerError!void {
     const air_tags = self.air.instructions.items(.tag);
 
     for (body) |inst| {
+        // TODO: remove now-redundant isUnused calls from AIR handler functions
+        if (self.liveness.isUnused(inst) and !self.air.mustLower(inst)) {
+            continue;
+        }
+
         const old_air_bookkeeping = self.air_bookkeeping;
         try self.ensureProcessDeathCapacity(Liveness.bpi);
 
diff --git a/src/arch/riscv64/CodeGen.zig b/src/arch/riscv64/CodeGen.zig
index 16d9548da7..f0ab8b3317 100644
--- a/src/arch/riscv64/CodeGen.zig
+++ b/src/arch/riscv64/CodeGen.zig
@@ -473,6 +473,11 @@ fn genBody(self: *Self, body: []const Air.Inst.Index) InnerError!void {
     const air_tags = self.air.instructions.items(.tag);
 
     for (body) |inst| {
+        // TODO: remove now-redundant isUnused calls from AIR handler functions
+        if (self.liveness.isUnused(inst) and !self.air.mustLower(inst)) {
+            continue;
+        }
+
         const old_air_bookkeeping = self.air_bookkeeping;
         try self.ensureProcessDeathCapacity(Liveness.bpi);
 
diff --git a/src/arch/sparc64/CodeGen.zig b/src/arch/sparc64/CodeGen.zig
index 197234c13b..2bcc1e1c4e 100644
--- a/src/arch/sparc64/CodeGen.zig
+++ b/src/arch/sparc64/CodeGen.zig
@@ -489,6 +489,11 @@ fn genBody(self: *Self, body: []const Air.Inst.Index) InnerError!void {
     const air_tags = self.air.instructions.items(.tag);
 
     for (body) |inst| {
+        // TODO: remove now-redundant isUnused calls from AIR handler functions
+        if (self.liveness.isUnused(inst) and !self.air.mustLower(inst)) {
+            continue;
+        }
+
         const old_air_bookkeeping = self.air_bookkeeping;
         try self.ensureProcessDeathCapacity(Liveness.bpi);
 
diff --git a/src/arch/x86_64/CodeGen.zig b/src/arch/x86_64/CodeGen.zig
index 33ff45d27d..5620ee2ad2 100644
--- a/src/arch/x86_64/CodeGen.zig
+++ b/src/arch/x86_64/CodeGen.zig
@@ -905,6 +905,11 @@ fn genBody(self: *Self, body: []const Air.Inst.Index) InnerError!void {
     const air_tags = self.air.instructions.items(.tag);
 
     for (body) |inst| {
+        // TODO: remove now-redundant isUnused calls from AIR handler functions
+        if (self.liveness.isUnused(inst) and !self.air.mustLower(inst)) {
+            continue;
+        }
+
         const old_air_bookkeeping = self.air_bookkeeping;
         try self.ensureProcessDeathCapacity(Liveness.bpi);
         if (builtin.mode == .Debug) {
diff --git a/src/codegen/spirv.zig b/src/codegen/spirv.zig
index 58da5539ac..87b72c6726 100644
--- a/src/codegen/spirv.zig
+++ b/src/codegen/spirv.zig
@@ -1507,6 +1507,11 @@ pub const DeclGen = struct {
     }
 
     fn genInst(self: *DeclGen, inst: Air.Inst.Index) !void {
+        // TODO: remove now-redundant isUnused calls from AIR handler functions
+        if (self.liveness.isUnused(inst) and !self.air.mustLower(inst)) {
+            return;
+        }
+
         const air_tags = self.air.instructions.items(.tag);
         const maybe_result_id: ?IdRef = switch (air_tags[inst]) {
             // zig fmt: off