Legalize some more i8/i16 intructions (#524)

* Legalize some more i8/i16 intructions

cranelift/filetests/isa/x86/legalize-byte-ops-i8.clif

@@ -0,0 +1,36 @@
+test compile
+target x86_64
+
+; regex: V=v\d+
+
+function u0:0(i8, i8) fast {
+fn0 = %black_box(i8)
+ss0 = explicit_slot 1 ; black box
+
+ebb0(v0: i8, v1: i8):
+    v99 = stack_addr.i64 ss0
+
+    ; check: istore8 $(V), $(V)
+
+    v2 = band v0, v1
+    store v2, v99
+    v3 = bor v0, v1
+    store v3, v99
+    v4 = bxor v0, v1
+    store v4, v99
+    v5 = bnot v0
+    store v5, v99
+    v6 = band_not v0, v1
+    store v6, v99
+    v7 = bor_not v0, v1
+    store v7, v99
+    v8 = bxor_not v0, v1
+    store v8, v99
+    v9 = band_imm v0, 42
+    store v9, v99
+    v10 = bor_imm v0, 42
+    store v10, v99
+    v11 = bxor_imm v0, 42
+    store v11, v99
+    return
+}

cranelift/filetests/isa/x86/legalize-icmp-i8.clif

@@ -0,0 +1,19 @@
+test compile
+target x86_64
+
+; regex: V=v\d+
+
+function u0:0(i8, i8) -> i8 fast {
+ebb0(v0: i8, v1: i8):
+    v2 = icmp_imm sle v0, 0
+    ; check: $(e1=$V) = sextend.i32 v0
+    ; nextln: v2 = icmp_imm sle $e1, 0
+    v3 = bint.i8 v2
+    v4 = icmp eq v0, v1
+    ; check: $(e2=$V) = uextend.i32 v0
+    ; nextln: $(e3=$V) = uextend.i32 v1
+    ; nextln: v4 = icmp eq $e2, $e3
+    v5 = bint.i8 v4
+    v6 = iadd v3, v5
+    return v6
+}

cranelift/filetests/isa/x86/legalize-shlr-i8.clif

@@ -0,0 +1,24 @@
+test compile
+target x86_64
+
+; regex: V=v\d+
+
+function u0:0(i8, i8) -> i8 fast {
+ebb0(v0: i8, v1: i8):
+    v2 = ishl v0, v1
+    ; check: $(e1=$V) = uextend.i32 v0
+    ; check: $(r1=$V) = ishl $e1, v1
+    ; check v2 = ireduce.i8 $r1
+    v3 = ushr v0, v1
+    ; check: $(e2=$V) = uextend.i32 v0
+    ; check: $(r2=$V) = ushr $e2, v1
+    ; check v2 = ireduce.i8 $r2
+    v4 = sshr v0, v1
+    ; check: $(e3=$V) = sextend.i32 v0
+    ; check: $(r3=$V) = sshr $e3, v1
+    ; check v2 = ireduce.i8 $r3
+
+    v5 = iadd v2, v3
+    v6 = iadd v4, v5
+    return v6
+}

cranelift/filetests/isa/x86/legalize-urem-i8.clif

@@ -0,0 +1,15 @@
+test compile
+target x86_64
+
+; regex: V=v\d+
+
+function u0:0(i8, i8) -> i8 fast {
+ebb0(v0: i8, v1: i8):
+    v2 = urem v0, v1
+    ; check: $(a=$V) = uextend.i32 v0
+    ; nextln: $(b=$V) = uextend.i32 v1
+    ; nextln: $(c=$V) = iconst.i32 0
+    ; nextln: $(V), $(r=$V) = x86_udivmodx $a, $c, $b
+    ; nextln: v2 = ireduce.i8 $r
+    return v2
+}