; The mask is redundant, and can be dropped:
; data outer>> nbits
; This is valid for both lshr and ashr in both positions and any combination.
+; We must *not* preserve 'exact' on that final right-shift.
define i32 @t0_lshr(i32 %data, i32 %nbits) {
; CHECK-LABEL: @t0_lshr(
; CHECK-NEXT: [[T0:%.*]] = shl i32 -1, [[NBITS:%.*]]
; CHECK-NEXT: [[T1:%.*]] = and i32 [[T0]], [[DATA:%.*]]
-; CHECK-NEXT: [[T2:%.*]] = lshr i32 [[T1]], [[NBITS]]
+; CHECK-NEXT: [[T2:%.*]] = lshr exact i32 [[T1]], [[NBITS]]
; CHECK-NEXT: ret i32 [[T2]]
;
%t0 = shl i32 -1, %nbits
%t1 = and i32 %t0, %data
- %t2 = lshr i32 %t1, %nbits
+ %t2 = lshr exact i32 %t1, %nbits ; while there, test that we *don't* propagate 'exact'
ret i32 %t2
}
define i32 @t1_sshr(i32 %data, i32 %nbits) {
; CHECK-LABEL: @t1_sshr(
; CHECK-NEXT: [[T0:%.*]] = shl i32 -1, [[NBITS:%.*]]
; CHECK-NEXT: [[T1:%.*]] = and i32 [[T0]], [[DATA:%.*]]
-; CHECK-NEXT: [[T2:%.*]] = ashr i32 [[T1]], [[NBITS]]
+; CHECK-NEXT: [[T2:%.*]] = ashr exact i32 [[T1]], [[NBITS]]
; CHECK-NEXT: ret i32 [[T2]]
;
%t0 = shl i32 -1, %nbits
%t1 = and i32 %t0, %data
- %t2 = ashr i32 %t1, %nbits
+ %t2 = ashr exact i32 %t1, %nbits ; while there, test that we *don't* propagate 'exact'
ret i32 %t2
}
ret i32 %t2
}
+; Commutativity
+
+declare i32 @gen32()
+
+define i32 @t11_commutative(i32 %nbits) {
+; CHECK-LABEL: @t11_commutative(
+; CHECK-NEXT: [[DATA:%.*]] = call i32 @gen32()
+; CHECK-NEXT: [[T0:%.*]] = shl i32 -1, [[NBITS:%.*]]
+; CHECK-NEXT: [[T1:%.*]] = and i32 [[DATA]], [[T0]]
+; CHECK-NEXT: [[T2:%.*]] = lshr i32 [[T1]], [[NBITS]]
+; CHECK-NEXT: ret i32 [[T2]]
+;
+ %data = call i32 @gen32()
+ %t0 = shl i32 -1, %nbits
+ %t1 = and i32 %data, %t0 ; swapped
+ %t2 = lshr i32 %t1, %nbits
+ ret i32 %t2
+}
+
; Negative tests
-define i32 @n11(i32 %data, i32 %nbits) {
-; CHECK-LABEL: @n11(
+define i32 @n12(i32 %data, i32 %nbits) {
+; CHECK-LABEL: @n12(
; CHECK-NEXT: [[T0:%.*]] = shl i32 2147483647, [[NBITS:%.*]]
; CHECK-NEXT: [[T1:%.*]] = and i32 [[T0]], [[DATA:%.*]]
; CHECK-NEXT: [[T2:%.*]] = lshr i32 [[T1]], [[NBITS]]
ret i32 %t2
}
-define i32 @n12(i32 %data, i32 %nbits0, i32 %nbits1) {
-; CHECK-LABEL: @n12(
+define i32 @n13(i32 %data, i32 %nbits0, i32 %nbits1) {
+; CHECK-LABEL: @n13(
; CHECK-NEXT: [[T0:%.*]] = shl i32 -1, [[NBITS0:%.*]]
; CHECK-NEXT: [[T1:%.*]] = and i32 [[T0]], [[DATA:%.*]]
; CHECK-NEXT: [[T2:%.*]] = lshr i32 [[T1]], [[NBITS1:%.*]]
ret i32 %t2
}
-define i32 @n13(i32 %data, i32 %nbits0, i32 %nbits1, i32 %nbits2) {
-; CHECK-LABEL: @n13(
+define i32 @n14(i32 %data, i32 %nbits0, i32 %nbits1, i32 %nbits2) {
+; CHECK-LABEL: @n14(
; CHECK-NEXT: [[T0:%.*]] = lshr i32 [[DATA:%.*]], [[NBITS0:%.*]]
; CHECK-NEXT: call void @use32(i32 [[T0]])
; CHECK-NEXT: [[T1:%.*]] = shl i32 [[T0]], [[NBITS1:%.*]]