[ValueTracking] Add pre-commit tests. NFC.

Author: dtcxzyw

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

@@ -343,5 +343,131 @@ exit:
   ret i8 %or2
 }
 
+define i32 @test_icmp_trunc1(i32 %x){
+; CHECK-LABEL: @test_icmp_trunc1(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[Y:%.*]] = trunc i32 [[X:%.*]] to i16
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i16 [[Y]], 7
+; CHECK-NEXT:    br i1 [[CMP]], label [[THEN:%.*]], label [[ELSE:%.*]]
+; CHECK:       then:
+; CHECK-NEXT:    [[Z:%.*]] = and i32 [[X]], 15
+; CHECK-NEXT:    ret i32 [[Z]]
+; CHECK:       else:
+; CHECK-NEXT:    ret i32 0
+;
+entry:
+  %y = trunc i32 %x to i16
+  %cmp = icmp eq i16 %y, 7
+  br i1 %cmp, label %then, label %else
+then:
+  %z = and i32 %x, 15
+  ret i32 %z
+else:
+  ret i32 0
+}
+
+define i64 @test_icmp_trunc2(i64 %x) {
+; CHECK-LABEL: @test_icmp_trunc2(
+; CHECK-NEXT:    [[CONV:%.*]] = trunc i64 [[X:%.*]] to i32
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i32 [[CONV]], 12
+; CHECK-NEXT:    br i1 [[CMP]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
+; CHECK:       if.then:
+; CHECK-NEXT:    [[SEXT:%.*]] = shl i64 [[X]], 32
+; CHECK-NEXT:    [[RET:%.*]] = ashr exact i64 [[SEXT]], 32
+; CHECK-NEXT:    ret i64 [[RET]]
+; CHECK:       if.else:
+; CHECK-NEXT:    ret i64 0
+;
+  %conv = trunc i64 %x to i32
+  %cmp = icmp sgt i32 %conv, 12
+  br i1 %cmp, label %if.then, label %if.else
+
+if.then:
+  %sext = shl i64 %x, 32
+  %ret = ashr exact i64 %sext, 32
+  ret i64 %ret
+if.else:
+  ret i64 0
+}
+
+define i64 @test_icmp_trunc3(i64 %n) {
+; CHECK-LABEL: @test_icmp_trunc3(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CONV:%.*]] = trunc i64 [[N:%.*]] to i32
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i32 [[CONV]], 96
+; CHECK-NEXT:    br i1 [[CMP]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
+; CHECK:       if.then:
+; CHECK-NEXT:    [[RET:%.*]] = and i64 [[N]], 4294967295
+; CHECK-NEXT:    ret i64 [[RET]]
+; CHECK:       if.else:
+; CHECK-NEXT:    ret i64 0
+;
+entry:
+  %conv = trunc i64 %n to i32
+  %cmp = icmp ult i32 %conv, 96
+  br i1 %cmp, label %if.then, label %if.else
+
+if.then:
+  %ret = and i64 %n, 4294967295
+  ret i64 %ret
+
+if.else:
+  ret i64 0
+}
+
+define i8 @test_icmp_trunc4(i64 %n) {
+; CHECK-LABEL: @test_icmp_trunc4(
+; CHECK-NEXT:    [[CONV:%.*]] = trunc i64 [[N:%.*]] to i32
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i32 [[CONV]], 10
+; CHECK-NEXT:    br i1 [[CMP]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
+; CHECK:       if.then:
+; CHECK-NEXT:    [[CONV2:%.*]] = trunc i64 [[N]] to i8
+; CHECK-NEXT:    [[ADD:%.*]] = add i8 [[CONV2]], 48
+; CHECK-NEXT:    ret i8 [[ADD]]
+; CHECK:       if.else:
+; CHECK-NEXT:    ret i8 0
+;
+  %conv = trunc i64 %n to i32
+  %cmp = icmp ult i32 %conv, 10
+  br i1 %cmp, label %if.then, label %if.else
+
+if.then:
+  %conv2 = trunc i64 %n to i8
+  %add = add i8 %conv2, 48
+  ret i8 %add
+
+if.else:
+  ret i8 0
+}
+
+define i64 @test_icmp_trunc5(i64 %n) {
+; CHECK-LABEL: @test_icmp_trunc5(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[SHR:%.*]] = ashr i64 [[N:%.*]], 47
+; CHECK-NEXT:    [[CONV1:%.*]] = trunc i64 [[SHR]] to i32
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i32 [[CONV1]], -13
+; CHECK-NEXT:    br i1 [[CMP]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
+; CHECK:       if.then:
+; CHECK-NEXT:    [[AND:%.*]] = and i64 [[SHR]], 4294967295
+; CHECK-NEXT:    [[NOT:%.*]] = xor i64 [[AND]], 4294967295
+; CHECK-NEXT:    ret i64 [[NOT]]
+; CHECK:       if.else:
+; CHECK-NEXT:    ret i64 13
+;
+entry:
+  %shr = ashr i64 %n, 47
+  %conv1 = trunc i64 %shr to i32
+  %cmp = icmp ugt i32 %conv1, -13
+  br i1 %cmp, label %if.then, label %if.else
+
+if.then:
+  %and = and i64 %shr, 4294967295
+  %not = xor i64 %and, 4294967295
+  ret i64 %not
+
+if.else:
+  ret i64 13
+}
+
 declare void @use(i1)
 declare void @sink(i8)