[ValueTracking] Add tests for computing known bits from (icmp eq (and/or x,y), C); NFC

Author: goldsteinn

llvm/test/Transforms/InstCombine/known-bits.ll

@@ -124,7 +124,6 @@ exit:
   ret i8 %or2
 }
 
-
 define i8 @test_cond_and_bothways(i8 %x) {
 ; CHECK-LABEL: @test_cond_and_bothways(
 ; CHECK-NEXT:    [[AND:%.*]] = and i8 [[X:%.*]], 91
@@ -181,8 +180,6 @@ exit:
   ret i8 %or2
 }
 
-
-
 define i8 @test_cond_and_commuted(i8 %x, i1 %c1, i1 %c2) {
 ; CHECK-LABEL: @test_cond_and_commuted(
 ; CHECK-NEXT:    [[AND:%.*]] = and i8 [[X:%.*]], 3
@@ -343,7 +340,7 @@ exit:
   ret i8 %or2
 }
 
-define i32 @test_icmp_trunc1(i32 %x){
+define i32 @test_icmp_trunc1(i32 %x) {
 ; CHECK-LABEL: @test_icmp_trunc1(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[Y:%.*]] = trunc i32 [[X:%.*]] to i16
@@ -365,7 +362,7 @@ else:
   ret i32 0
 }
 
-define i32 @test_icmp_trunc_assume(i32 %x){
+define i32 @test_icmp_trunc_assume(i32 %x) {
 ; CHECK-LABEL: @test_icmp_trunc_assume(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[Y:%.*]] = trunc i32 [[X:%.*]] to i16
@@ -532,7 +529,110 @@ if.else:
   ret i1 %other
 }
 
+define i8 @and_eq_bits_must_be_set(i8 %x, i8 %y) {
+; CHECK-LABEL: @and_eq_bits_must_be_set(
+; CHECK-NEXT:    [[XY:%.*]] = and i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[XY]], 123
+; CHECK-NEXT:    call void @llvm.assume(i1 [[CMP]])
+; CHECK-NEXT:    [[R:%.*]] = and i8 [[X]], 1
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %xy = and i8 %x, %y
+  %cmp = icmp eq i8 %xy, 123
+  call void @llvm.assume(i1 %cmp)
+  %r = and i8 %x, 1
+  ret i8 %r
+}
+
+define i8 @and_eq_bits_must_be_set2(i8 %x, i8 %y) {
+; CHECK-LABEL: @and_eq_bits_must_be_set2(
+; CHECK-NEXT:    [[XY:%.*]] = and i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[XY]], 123
+; CHECK-NEXT:    call void @llvm.assume(i1 [[CMP]])
+; CHECK-NEXT:    [[R:%.*]] = and i8 [[Y]], 11
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %xy = and i8 %x, %y
+  %cmp = icmp eq i8 %xy, 123
+  call void @llvm.assume(i1 %cmp)
+  %r = and i8 %y, 11
+  ret i8 %r
+}
+
+define i8 @and_eq_bits_must_be_set2_partial_fail(i8 %x, i8 %y) {
+; CHECK-LABEL: @and_eq_bits_must_be_set2_partial_fail(
+; CHECK-NEXT:    [[XY:%.*]] = and i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[XY]], 123
+; CHECK-NEXT:    call void @llvm.assume(i1 [[CMP]])
+; CHECK-NEXT:    [[R:%.*]] = and i8 [[Y]], 111
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %xy = and i8 %x, %y
+  %cmp = icmp eq i8 %xy, 123
+  call void @llvm.assume(i1 %cmp)
+  %r = and i8 %y, 111
+  ret i8 %r
+}
+
+define i8 @or_eq_bits_must_be_unset(i8 %x, i8 %y) {
+; CHECK-LABEL: @or_eq_bits_must_be_unset(
+; CHECK-NEXT:    [[XY:%.*]] = or i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[XY]], 124
+; CHECK-NEXT:    call void @llvm.assume(i1 [[CMP]])
+; CHECK-NEXT:    [[R:%.*]] = and i8 [[X]], 3
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %xy = or i8 %x, %y
+  %cmp = icmp eq i8 %xy, 124
+  call void @llvm.assume(i1 %cmp)
+  %r = and i8 %x, 3
+  ret i8 %r
+}
+
+define i8 @or_eq_bits_must_be_unset2(i8 %x, i8 %y) {
+; CHECK-LABEL: @or_eq_bits_must_be_unset2(
+; CHECK-NEXT:    [[XY:%.*]] = or i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[XY]], 124
+; CHECK-NEXT:    call void @llvm.assume(i1 [[CMP]])
+; CHECK-NEXT:    [[R:%.*]] = and i8 [[Y]], 1
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %xy = or i8 %x, %y
+  %cmp = icmp eq i8 %xy, 124
+  call void @llvm.assume(i1 %cmp)
+  %r = and i8 %y, 1
+  ret i8 %r
+}
 
+define i8 @or_eq_bits_must_be_unset2_partial_fail(i8 %x, i8 %y) {
+; CHECK-LABEL: @or_eq_bits_must_be_unset2_partial_fail(
+; CHECK-NEXT:    [[XY:%.*]] = or i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[XY]], 124
+; CHECK-NEXT:    call void @llvm.assume(i1 [[CMP]])
+; CHECK-NEXT:    [[R:%.*]] = and i8 [[Y]], 7
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %xy = or i8 %x, %y
+  %cmp = icmp eq i8 %xy, 124
+  call void @llvm.assume(i1 %cmp)
+  %r = and i8 %y, 7
+  ret i8 %r
+}
+
+define i8 @or_ne_bits_must_be_unset2_fail(i8 %x, i8 %y) {
+; CHECK-LABEL: @or_ne_bits_must_be_unset2_fail(
+; CHECK-NEXT:    [[XY:%.*]] = or i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i8 [[XY]], 124
+; CHECK-NEXT:    call void @llvm.assume(i1 [[CMP]])
+; CHECK-NEXT:    [[R:%.*]] = and i8 [[X]], 3
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %xy = or i8 %x, %y
+  %cmp = icmp ne i8 %xy, 124
+  call void @llvm.assume(i1 %cmp)
+  %r = and i8 %x, 3
+  ret i8 %r
+}
 
 declare void @use(i1)
 declare void @sink(i8)