[InstCombine] add tests from D32285 to show current problems; NFC

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@302475 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Sanjay Patel 2017-05-08 22:33:20 +00:00
parent cca9d00b74
commit c4c34cce40

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@ -1432,3 +1432,41 @@ define <2 x i32> @test90() {
%tmp6 = bitcast <4 x half> <half undef, half undef, half undef, half 0xH3C00> to <2 x i32>
ret <2 x i32> %tmp6
}
; Do not optimize to ashr i64 (shift by 48 > 96 - 64)
define i64 @test91(i64 %A) {
; CHECK-LABEL: @test91(
; CHECK-NEXT: [[C:%.*]] = ashr i64 %A, 48
; CHECK-NEXT: ret i64 [[C]]
;
%B = sext i64 %A to i96
%C = lshr i96 %B, 48
%D = trunc i96 %C to i64
ret i64 %D
}
; Do optimize to ashr i64 (shift by 32 <= 96 - 64)
define i64 @test92(i64 %A) {
; CHECK-LABEL: @test92(
; CHECK-NEXT: [[C:%.*]] = ashr i64 %A, 32
; CHECK-NEXT: ret i64 [[C]]
;
%B = sext i64 %A to i96
%C = lshr i96 %B, 32
%D = trunc i96 %C to i64
ret i64 %D
}
; When optimizing to ashr i32, don't shift by more than 31.
define i32 @test93(i32 %A) {
; CHECK-LABEL: @test93(
; CHECK-NEXT: [[B:%.*]] = sext i32 %A to i96
; CHECK-NEXT: [[C:%.*]] = lshr i96 [[B]], 64
; CHECK-NEXT: [[D:%.*]] = trunc i96 [[C]] to i32
; CHECK-NEXT: ret i32 [[D]]
;
%B = sext i32 %A to i96
%C = lshr i96 %B, 64
%D = trunc i96 %C to i32
ret i32 %D
}