[NFC][InstCombine] Add baseline tests for canonicalizing "and, add", "or, add", "xor, add"

[emgullufsen]

Summary

Baseline tests for canonicalizing "logic op, add"

((x + C1) & C2) --> ((x & C2) + C1)     
((x + C1) ^ C2) --> ((x ^ C2) + C1)     
((x + C1) | C2) --> ((x | C2) + C1)

for suitable constants C1 and C2.

[emgullufsen]

I need a few more test cases I'd neglected (multiple use negative case at least) I am realizing, will update patch.

[emgullufsen]

Added multiple use negative tests

[RKSimon]

vector test coverage?

[emgullufsen]

Added vector tests

[foad]

Looks fine but please just check the comments.

llvm/test/Transforms/InstCombine/and-xor-or.ll

4378

112 is not 0xFF800000

[emgullufsen]

Address comments (bad hex values in comments for 112 and 15)

[spatel]

LGTM

llvm/test/Transforms/InstCombine/and-xor-or.ll

;
   %t2 = icmp eq i8 %x, 2
   %t3 = and i8 %x, 1
   %t4 = zext i1 %t2 to i32
   %t5 = zext i8 %t3 to i32
   %t6 = and i32 %t4, %t5
   %t7 = icmp ne i32 %t6, 0
   ret i1 %t7
 }
+
+define i32 @canonicalize_logic_first_or_0(i32 %x) {
+; CHECK-LABEL: define {{[^@]+}}@canonicalize_logic_first_or_0
+; CHECK-SAME: (i32 [[X:%.*]]) {
+; CHECK-NEXT:    [[A:%.*]] = add i32 [[X]], 112
+; CHECK-NEXT:    [[R:%.*]] = or i32 [[A]], 15
+; CHECK-NEXT:    ret i32 [[R]]
+;
+  %a = add i32 %x, 112 ; 01110000
+  %r = or i32 %a, 15   ; 00001111
+  ret i32 %r
+}
+
+define i32 @canonicalize_logic_first_negative_or_0(i32 %x) {
+; CHECK-LABEL: define {{[^@]+}}@canonicalize_logic_first_negative_or_0
+; CHECK-SAME: (i32 [[X:%.*]]) {
+; CHECK-NEXT:    [[A:%.*]] = add i32 [[X]], 112
+; CHECK-NEXT:    [[R:%.*]] = or i32 [[A]], 16
+; CHECK-NEXT:    ret i32 [[R]]
+;
+  %a = add i32 %x, 112 ; 01110000
+  %r = or i32 %a, 16   ; 00010000
+  ret i32 %r
+}
+
+define i8 @canonicalize_logic_first_and_0(i8 %x) {
+; CHECK-LABEL: define {{[^@]+}}@canonicalize_logic_first_and_0
+; CHECK-SAME: (i8 [[X:%.*]]) {
+; CHECK-NEXT:    [[B:%.*]] = add i8 [[X]], 48
+; CHECK-NEXT:    [[R:%.*]] = and i8 [[B]], -10
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %b = add i8 %x, 48    ;  00110000
+  %r = and i8 %b, -10   ;  11110110
+  ret i8 %r
+}
+
+define i8 @canonicalize_logic_first_negative_and_0(i8 %x) {
+; CHECK-LABEL: define {{[^@]+}}@canonicalize_logic_first_negative_and_0
+; CHECK-SAME: (i8 [[X:%.*]]) {
+; CHECK-NEXT:    [[B:%.*]] = add i8 [[X]], 48
+; CHECK-NEXT:    [[R:%.*]] = and i8 [[B]], -26
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %b = add i8 %x, 48    ;  00110000
+  %r = and i8 %b, -26   ;  11100110
+  ret i8 %r
+}
+
+define i8 @canonicalize_logic_first_xor_0(i8 %x) {
+; CHECK-LABEL: define {{[^@]+}}@canonicalize_logic_first_xor_0
+; CHECK-SAME: (i8 [[X:%.*]]) {
+; CHECK-NEXT:    [[A:%.*]] = add i8 [[X]], 96
+; CHECK-NEXT:    [[R:%.*]] = xor i8 [[A]], 31
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %a = add i8 %x, 96  ; 01100000
+  %r = xor i8 %a, 31  ; 00011111
+  ret i8 %r
+}
+
+define i8 @canonicalize_logic_first_negative_xor_0(i8 %x) {
+; CHECK-LABEL: define {{[^@]+}}@canonicalize_logic_first_negative_xor_0
+; CHECK-SAME: (i8 [[X:%.*]]) {
+; CHECK-NEXT:    [[A:%.*]] = add i8 [[X]], 96
+; CHECK-NEXT:    [[R:%.*]] = xor i8 [[A]], 32
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %a = add i8 %x, 96  ; 01100000
+  %r = xor i8 %a, 32  ; 00100000
+  ret i8 %r
+}