xref: /aosp_15_r20/external/llvm/test/Transforms/InstCombine/lshr-phi.ll (revision 9880d6810fe72a1726cb53787c6711e909410d58)
1*9880d681SAndroid Build Coastguard Worker; RUN: opt < %s -instcombine -S > %t
2*9880d681SAndroid Build Coastguard Worker; RUN: not grep lshr %t
3*9880d681SAndroid Build Coastguard Worker; RUN: grep add %t | count 1
4*9880d681SAndroid Build Coastguard Worker
5*9880d681SAndroid Build Coastguard Worker; Instcombine should be able to eliminate the lshr, because only
6*9880d681SAndroid Build Coastguard Worker; bits in the operand which might be non-zero will be shifted
7*9880d681SAndroid Build Coastguard Worker; off the end.
8*9880d681SAndroid Build Coastguard Worker
9*9880d681SAndroid Build Coastguard Workerdefine i32 @hash_string(i8* nocapture %key) nounwind readonly {
10*9880d681SAndroid Build Coastguard Workerentry:
11*9880d681SAndroid Build Coastguard Worker	%t0 = load i8, i8* %key, align 1		; <i8> [#uses=1]
12*9880d681SAndroid Build Coastguard Worker	%t1 = icmp eq i8 %t0, 0		; <i1> [#uses=1]
13*9880d681SAndroid Build Coastguard Worker	br i1 %t1, label %bb2, label %bb
14*9880d681SAndroid Build Coastguard Worker
15*9880d681SAndroid Build Coastguard Workerbb:		; preds = %bb, %entry
16*9880d681SAndroid Build Coastguard Worker	%indvar = phi i64 [ 0, %entry ], [ %tmp, %bb ]		; <i64> [#uses=2]
17*9880d681SAndroid Build Coastguard Worker	%k.04 = phi i32 [ 0, %entry ], [ %t8, %bb ]		; <i32> [#uses=2]
18*9880d681SAndroid Build Coastguard Worker	%cp.05 = getelementptr i8, i8* %key, i64 %indvar		; <i8*> [#uses=1]
19*9880d681SAndroid Build Coastguard Worker	%t2 = shl i32 %k.04, 1		; <i32> [#uses=1]
20*9880d681SAndroid Build Coastguard Worker	%t3 = lshr i32 %k.04, 14		; <i32> [#uses=1]
21*9880d681SAndroid Build Coastguard Worker	%t4 = add i32 %t2, %t3		; <i32> [#uses=1]
22*9880d681SAndroid Build Coastguard Worker	%t5 = load i8, i8* %cp.05, align 1		; <i8> [#uses=1]
23*9880d681SAndroid Build Coastguard Worker	%t6 = sext i8 %t5 to i32		; <i32> [#uses=1]
24*9880d681SAndroid Build Coastguard Worker	%t7 = xor i32 %t6, %t4		; <i32> [#uses=1]
25*9880d681SAndroid Build Coastguard Worker	%t8 = and i32 %t7, 16383		; <i32> [#uses=2]
26*9880d681SAndroid Build Coastguard Worker	%tmp = add i64 %indvar, 1		; <i64> [#uses=2]
27*9880d681SAndroid Build Coastguard Worker	%scevgep = getelementptr i8, i8* %key, i64 %tmp		; <i8*> [#uses=1]
28*9880d681SAndroid Build Coastguard Worker	%t9 = load i8, i8* %scevgep, align 1		; <i8> [#uses=1]
29*9880d681SAndroid Build Coastguard Worker	%t10 = icmp eq i8 %t9, 0		; <i1> [#uses=1]
30*9880d681SAndroid Build Coastguard Worker	br i1 %t10, label %bb2, label %bb
31*9880d681SAndroid Build Coastguard Worker
32*9880d681SAndroid Build Coastguard Workerbb2:		; preds = %bb, %entry
33*9880d681SAndroid Build Coastguard Worker	%k.0.lcssa = phi i32 [ 0, %entry ], [ %t8, %bb ]		; <i32> [#uses=1]
34*9880d681SAndroid Build Coastguard Worker	ret i32 %k.0.lcssa
35*9880d681SAndroid Build Coastguard Worker}
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