; RUN: opt < %s -instcombine -S | FileCheck %s ; With left shift, the comparison should not be modified. ; CHECK-LABEL: @test_shift_and_cmp_not_changed1( ; CHECK: icmp slt i8 %andp, 32 define i1 @test_shift_and_cmp_not_changed1(i8 %p) #0 { entry: %shlp = shl i8 %p, 5 %andp = and i8 %shlp, -64 %cmp = icmp slt i8 %andp, 32 ret i1 %cmp } ; With arithmetic right shift, the comparison should not be modified. ; CHECK-LABEL: @test_shift_and_cmp_not_changed2( ; CHECK: icmp slt i8 %andp, 32 define i1 @test_shift_and_cmp_not_changed2(i8 %p) #0 { entry: %shlp = ashr i8 %p, 5 %andp = and i8 %shlp, -64 %cmp = icmp slt i8 %andp, 32 ret i1 %cmp } ; This should simplify functionally to the left shift case. ; The extra input parameter should be optimized away. ; CHECK-LABEL: @test_shift_and_cmp_changed1( ; CHECK: %andp = shl i8 %p, 5 ; CHECK-NEXT: %shl = and i8 %andp, -64 ; CHECK-NEXT: %cmp = icmp slt i8 %shl, 32 define i1 @test_shift_and_cmp_changed1(i8 %p, i8 %q) #0 { entry: %andp = and i8 %p, 6 %andq = and i8 %q, 8 %or = or i8 %andq, %andp %shl = shl i8 %or, 5 %ashr = ashr i8 %shl, 5 %cmp = icmp slt i8 %ashr, 1 ret i1 %cmp } ; Unsigned compare allows a transformation to compare against 0. ; CHECK-LABEL: @test_shift_and_cmp_changed2( ; CHECK: icmp eq i8 %andp, 0 define i1 @test_shift_and_cmp_changed2(i8 %p) #0 { entry: %shlp = shl i8 %p, 5 %andp = and i8 %shlp, -64 %cmp = icmp ult i8 %andp, 32 ret i1 %cmp } ; nsw on the shift should not affect the comparison. ; CHECK-LABEL: @test_shift_and_cmp_changed3( ; CHECK: icmp slt i8 %andp, 32 define i1 @test_shift_and_cmp_changed3(i8 %p) #0 { entry: %shlp = shl nsw i8 %p, 5 %andp = and i8 %shlp, -64 %cmp = icmp slt i8 %andp, 32 ret i1 %cmp } ; Logical shift right allows a return true because the 'and' guarantees no bits are set. ; CHECK-LABEL: @test_shift_and_cmp_changed4( ; CHECK: ret i1 true define i1 @test_shift_and_cmp_changed4(i8 %p) #0 { entry: %shlp = lshr i8 %p, 5 %andp = and i8 %shlp, -64 %cmp = icmp slt i8 %andp, 32 ret i1 %cmp }