shift-folding.ll
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; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc < %s -mtriple=i686-unknown-unknown -verify-coalescing | FileCheck %s
define i32* @test1(i32* %P, i32 %X) {
; CHECK-LABEL: test1:
; CHECK: # %bb.0:
; CHECK-NEXT: movl {{[0-9]+}}(%esp), %eax
; CHECK-NEXT: andl $-4, %eax
; CHECK-NEXT: addl {{[0-9]+}}(%esp), %eax
; CHECK-NEXT: retl
%Y = lshr i32 %X, 2
%gep.upgrd.1 = zext i32 %Y to i64
%P2 = getelementptr i32, i32* %P, i64 %gep.upgrd.1
ret i32* %P2
}
define i32* @test2(i32* %P, i32 %X) {
; CHECK-LABEL: test2:
; CHECK: # %bb.0:
; CHECK-NEXT: movl {{[0-9]+}}(%esp), %eax
; CHECK-NEXT: shll $4, %eax
; CHECK-NEXT: addl {{[0-9]+}}(%esp), %eax
; CHECK-NEXT: retl
%Y = shl i32 %X, 2
%gep.upgrd.2 = zext i32 %Y to i64
%P2 = getelementptr i32, i32* %P, i64 %gep.upgrd.2
ret i32* %P2
}
define i32* @test3(i32* %P, i32 %X) {
; CHECK-LABEL: test3:
; CHECK: # %bb.0:
; CHECK-NEXT: movl {{[0-9]+}}(%esp), %eax
; CHECK-NEXT: andl $-4, %eax
; CHECK-NEXT: addl {{[0-9]+}}(%esp), %eax
; CHECK-NEXT: retl
%Y = ashr i32 %X, 2
%P2 = getelementptr i32, i32* %P, i32 %Y
ret i32* %P2
}
define fastcc i32 @test4(i32* %d) {
; CHECK-LABEL: test4:
; CHECK: # %bb.0:
; CHECK-NEXT: movzbl 3(%ecx), %eax
; CHECK-NEXT: retl
%tmp4 = load i32, i32* %d
%tmp512 = lshr i32 %tmp4, 24
ret i32 %tmp512
}
; Ensure that we don't fold away shifts which have multiple uses, as they are
; just re-introduced for the second use.
define i64 @test5(i16 %i, i32* %arr) {
; CHECK-LABEL: test5:
; CHECK: # %bb.0:
; CHECK-NEXT: movl {{[0-9]+}}(%esp), %ecx
; CHECK-NEXT: movzwl {{[0-9]+}}(%esp), %eax
; CHECK-NEXT: shrl $11, %eax
; CHECK-NEXT: xorl %edx, %edx
; CHECK-NEXT: addl (%ecx,%eax,4), %eax
; CHECK-NEXT: setb %dl
; CHECK-NEXT: retl
%i.zext = zext i16 %i to i32
%index = lshr i32 %i.zext, 11
%index.zext = zext i32 %index to i64
%val.ptr = getelementptr inbounds i32, i32* %arr, i64 %index.zext
%val = load i32, i32* %val.ptr
%val.zext = zext i32 %val to i64
%sum = add i64 %val.zext, %index.zext
ret i64 %sum
}
; We should not crash because an undef shift was created.
define i32 @overshift(i32 %a) {
; CHECK-LABEL: overshift:
; CHECK: # %bb.0:
; CHECK-NEXT: retl
%shr = lshr i32 %a, 33
%xor = xor i32 1, %shr
ret i32 %xor
}