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hanchenye-llvm-project/llvm/test/Transforms/InstCombine/icmp-logical.ll

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InstCombine: look for masked compares with subset relation Even in cases which aren't universally optimisable like "(A & B) != 0 && (A & C) != 0", the masks can make one of the comparisons completely redundant. In this case, since we've gone to the effort of spotting masked comparisons we should combine them. rdar://problem/7625728 llvm-svn: 189930
2013-09-04 19:57:13 +08:00
; RUN: opt -instcombine -S -o - %s | FileCheck %s
define i1 @masked_and_notallzeroes(i32 %A) {
; CHECK-LABEL: @masked_and_notallzeroes
; CHECK: [[MASK:%.*]] = and i32 %A, 7
; CHECK: icmp ne i32 [[MASK]], 0
; CHECK-NOT: and i32 %A, 39
; CHECK: ret i1
%mask1 = and i32 %A, 7
%tst1 = icmp ne i32 %mask1, 0
%mask2 = and i32 %A, 39
%tst2 = icmp ne i32 %mask2, 0
%res = and i1 %tst1, %tst2
ret i1 %res
}
define i1 @masked_or_allzeroes(i32 %A) {
; CHECK-LABEL: @masked_or_allzeroes
; CHECK: [[MASK:%.*]] = and i32 %A, 7
; CHECK: icmp eq i32 [[MASK]], 0
; CHECK-NOT: and i32 %A, 39
; CHECK: ret i1
%mask1 = and i32 %A, 7
%tst1 = icmp eq i32 %mask1, 0
%mask2 = and i32 %A, 39
%tst2 = icmp eq i32 %mask2, 0
%res = or i1 %tst1, %tst2
ret i1 %res
}
define i1 @masked_and_notallones(i32 %A) {
; CHECK-LABEL: @masked_and_notallones
; CHECK: [[MASK:%.*]] = and i32 %A, 7
; CHECK: icmp ne i32 [[MASK]], 7
; CHECK-NOT: and i32 %A, 39
; CHECK: ret i1
%mask1 = and i32 %A, 7
%tst1 = icmp ne i32 %mask1, 7
%mask2 = and i32 %A, 39
%tst2 = icmp ne i32 %mask2, 39
%res = and i1 %tst1, %tst2
ret i1 %res
}
define i1 @masked_or_allones(i32 %A) {
; CHECK-LABEL: @masked_or_allones
; CHECK: [[MASK:%.*]] = and i32 %A, 7
; CHECK: icmp eq i32 [[MASK]], 7
; CHECK-NOT: and i32 %A, 39
; CHECK: ret i1
%mask1 = and i32 %A, 7
%tst1 = icmp eq i32 %mask1, 7
%mask2 = and i32 %A, 39
%tst2 = icmp eq i32 %mask2, 39
%res = or i1 %tst1, %tst2
ret i1 %res
}
define i1 @masked_and_notA(i32 %A) {
; CHECK-LABEL: @masked_and_notA
; CHECK: [[MASK:%.*]] = and i32 %A, 39
; CHECK: icmp ne i32 [[MASK]], %A
; CHECK-NOT: and i32 %A, 7
; CHECK: ret i1
%mask1 = and i32 %A, 7
%tst1 = icmp ne i32 %mask1, %A
%mask2 = and i32 %A, 39
%tst2 = icmp ne i32 %mask2, %A
%res = and i1 %tst1, %tst2
ret i1 %res
}
define i1 @masked_or_A(i32 %A) {
; CHECK-LABEL: @masked_or_A
; CHECK: [[MASK:%.*]] = and i32 %A, 39
; CHECK: icmp eq i32 [[MASK]], %A
; CHECK-NOT: and i32 %A, 7
; CHECK: ret i1
%mask1 = and i32 %A, 7
%tst1 = icmp eq i32 %mask1, %A
%mask2 = and i32 %A, 39
%tst2 = icmp eq i32 %mask2, %A
%res = or i1 %tst1, %tst2
ret i1 %res
}
define i1 @masked_or_allzeroes_notoptimised(i32 %A) {
; CHECK-LABEL: @masked_or_allzeroes_notoptimised
; CHECK: [[MASK:%.*]] = and i32 %A, 15
; CHECK: icmp eq i32 [[MASK]], 0
; CHECK: [[MASK:%.*]] = and i32 %A, 39
; CHECK: icmp eq i32 [[MASK]], 0
; CHECK: ret i1
%mask1 = and i32 %A, 15
%tst1 = icmp eq i32 %mask1, 0
%mask2 = and i32 %A, 39
%tst2 = icmp eq i32 %mask2, 0
%res = or i1 %tst1, %tst2
ret i1 %res
}
InstCombine: allow unmasked icmps to be combined with logical ops "(icmp op i8 A, B)" is equivalent to "(icmp op i8 (A & 0xff), B)" as a degenerate case. Allowing this as a "masked" comparison when analysing "(icmp) &/| (icmp)" allows us to combine them in more cases. rdar://problem/7625728 llvm-svn: 189931
2013-09-04 19:57:17 +08:00
define i1 @nomask_lhs(i32 %in) {
; CHECK-LABEL: @nomask_lhs
; CHECK: [[MASK:%.*]] = and i32 %in, 1
; CHECK: icmp eq i32 [[MASK]], 0
; CHECK-NOT: icmp
; CHECK: ret i1
%tst1 = icmp eq i32 %in, 0
%masked = and i32 %in, 1
%tst2 = icmp eq i32 %masked, 0
%val = or i1 %tst1, %tst2
ret i1 %val
}
define i1 @nomask_rhs(i32 %in) {
; CHECK-LABEL: @nomask_rhs
; CHECK: [[MASK:%.*]] = and i32 %in, 1
; CHECK: icmp eq i32 [[MASK]], 0
; CHECK-NOT: icmp
; CHECK: ret i1
%masked = and i32 %in, 1
%tst1 = icmp eq i32 %masked, 0
%tst2 = icmp eq i32 %in, 0
%val = or i1 %tst1, %tst2
ret i1 %val
}