From c4b83ea02102611a85f75b189f0803d9b6a335c2 Mon Sep 17 00:00:00 2001
From: gracefu <81774659+gracefuu@users.noreply.github.com>
Date: Fri, 9 Apr 2021 13:51:00 +0800
Subject: stage2 x86_64: implement integer mul

This was also an experiment to see if it were easier to implement a new
feature when using the instruction encoder.

Verdict: It's not that much easier, but I think it's certainly much more
readable, because the description of the Instruction annotates what each
field means. Right now, precise knowledge of x86_64 instructions is
still required because things like when to set the 64-bit flag, how to
read x86_64 instruction references, etc. are still not automatically
done for you.

In the future, this interface might make it sligtly easier to write an
assembler for x86_64, by abstracting the bit-fiddling aspects of
instruction encoding.
---
 src/Sema.zig | 7 +++++++
 1 file changed, 7 insertions(+)

(limited to 'src/Sema.zig')

diff --git a/src/Sema.zig b/src/Sema.zig
index 98bff5bf23..74af84b078 100644
--- a/src/Sema.zig
+++ b/src/Sema.zig
@@ -3885,6 +3885,13 @@ fn analyzeArithmetic(
                         try Module.floatSub(sema.arena, scalar_type, src, lhs_val, rhs_val);
                     break :blk val;
                 },
+                .mul => blk: {
+                    const val = if (is_int)
+                        try Module.intMul(sema.arena, lhs_val, rhs_val)
+                    else
+                        try Module.floatMul(sema.arena, scalar_type, src, lhs_val, rhs_val);
+                    break :blk val;
+                },
                 else => return sema.mod.fail(&block.base, src, "TODO Implement arithmetic operand '{s}'", .{@tagName(zir_tag)}),
             };
 
-- 
cgit v1.2.3


From 613f39eb622d341d036ef418b19778d1f04d5a47 Mon Sep 17 00:00:00 2001
From: gracefu <81774659+gracefuu@users.noreply.github.com>
Date: Sat, 10 Apr 2021 14:01:09 +0800
Subject: stage2 x86_64: fix comptime integer multiplication when rhs=0

Co-authored-by: joachimschmidt557 <joachim.schmidt557@outlook.com>
---
 src/Sema.zig | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

(limited to 'src/Sema.zig')

diff --git a/src/Sema.zig b/src/Sema.zig
index 74af84b078..65a196911e 100644
--- a/src/Sema.zig
+++ b/src/Sema.zig
@@ -3864,10 +3864,15 @@ fn analyzeArithmetic(
             // incase rhs is 0, simply return lhs without doing any calculations
             // TODO Once division is implemented we should throw an error when dividing by 0.
             if (rhs_val.compareWithZero(.eq)) {
-                return sema.mod.constInst(sema.arena, src, .{
-                    .ty = scalar_type,
-                    .val = lhs_val,
-                });
+                switch (zir_tag) {
+                    .add, .addwrap, .sub, .subwrap => {
+                        return sema.mod.constInst(sema.arena, src, .{
+                            .ty = scalar_type,
+                            .val = lhs_val,
+                        });
+                    },
+                    else => {},
+                }
             }
 
             const value = switch (zir_tag) {
-- 
cgit v1.2.3