This patch implements optimization as mentioned in PR19753: Optimize comparisons with "ashr/lshr exact" of a constanst.

It handles the errors which were seen in PR19958 where wrong code was being emitted due to earlier patch.
Added code for lshr as well as non-exact right shifts.

It implements : 
(icmp eq/ne (ashr/lshr const2, A), const1)" ->
(icmp eq/ne A, Log2(const2/const1)) ->
(icmp eq/ne A, Log2(const2) - Log2(const1))

Differential Revision: http://reviews.llvm.org/D4068
 


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213678 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Suyog Sarda 2014-07-22 19:19:36 +00:00
parent 3326ee444a
commit c9ea25fc51
3 changed files with 772 additions and 0 deletions

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@ -172,6 +172,8 @@ public:
ConstantInt *DivRHS);
Instruction *FoldICmpShrCst(ICmpInst &ICI, BinaryOperator *DivI,
ConstantInt *DivRHS);
Instruction *FoldICmpCstShrCst(ICmpInst &I, Value *Op, Value *A,
ConstantInt *CI1, ConstantInt *CI2);
Instruction *FoldICmpAddOpCst(Instruction &ICI, Value *X, ConstantInt *CI,
ICmpInst::Predicate Pred);
Instruction *FoldGEPICmp(GEPOperator *GEPLHS, Value *RHS,

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@ -1044,6 +1044,90 @@ Instruction *InstCombiner::FoldICmpShrCst(ICmpInst &ICI, BinaryOperator *Shr,
return nullptr;
}
/// FoldICmpCstShrCst - Handle "(icmp eq/ne (ashr/lshr const2, A), const1)" ->
/// (icmp eq/ne A, Log2(const2/const1)) ->
/// (icmp eq/ne A, Log2(const2) - Log2(const1)).
Instruction *InstCombiner::FoldICmpCstShrCst(ICmpInst &I, Value *Op, Value *A,
ConstantInt *CI1,
ConstantInt *CI2) {
assert(I.isEquality() && "Cannot fold icmp gt/lt");
auto getConstant = [&I, this](bool IsTrue) {
if (I.getPredicate() == I.ICMP_NE)
IsTrue = !IsTrue;
return ReplaceInstUsesWith(I, ConstantInt::get(I.getType(), IsTrue));
};
auto getICmp = [&I](CmpInst::Predicate Pred, Value *LHS, Value *RHS) {
if (I.getPredicate() == I.ICMP_NE)
Pred = CmpInst::getInversePredicate(Pred);
return new ICmpInst(Pred, LHS, RHS);
};
APInt AP1 = CI1->getValue();
APInt AP2 = CI2->getValue();
if (!AP1) {
if (!AP2) {
// Both Constants are 0.
return getConstant(true);
}
if (cast<BinaryOperator>(Op)->isExact())
return getConstant(false);
if (AP2.isNegative()) {
// MSB is set, so a lshr with a large enough 'A' would be undefined.
return getConstant(false);
}
// 'A' must be large enough to shift out the highest set bit.
return getICmp(I.ICMP_UGT, A,
ConstantInt::get(A->getType(), AP2.logBase2()));
}
if (!AP2) {
// Shifting 0 by any value gives 0.
return getConstant(false);
}
bool IsAShr = isa<AShrOperator>(Op);
if (AP1 == AP2) {
if (AP1.isAllOnesValue() && IsAShr) {
// Arithmatic shift of -1 is always -1.
return getConstant(true);
}
return getICmp(I.ICMP_EQ, A, ConstantInt::getNullValue(A->getType()));
}
if (IsAShr) {
if (AP1.isNegative() != AP2.isNegative()) {
// Arithmetic shift will never change the sign.
return getConstant(false);
}
// Both the constants are negative, take their positive to calculate
// log.
if (AP1.isNegative()) {
AP1 = -AP1;
AP2 = -AP2;
}
}
if (AP1.ugt(AP2)) {
// Right-shifting will not increase the value.
return getConstant(false);
}
// Get the distance between the highest bit that's set.
int Shift = AP2.logBase2() - AP1.logBase2();
// Use lshr here, since we've canonicalized to +ve numbers.
if (AP1 == AP2.lshr(Shift))
return getICmp(I.ICMP_EQ, A, ConstantInt::get(A->getType(), Shift));
// Shifting const2 will never be equal to const1.
return getConstant(false);
}
/// visitICmpInstWithInstAndIntCst - Handle "icmp (instr, intcst)".
///
@ -2469,6 +2553,15 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) {
Builder->getInt(CI->getValue()-1));
}
// (icmp eq/ne (ashr/lshr const2, A), const1)
if (I.isEquality()) {
ConstantInt *CI2;
if (match(Op0, m_AShr(m_ConstantInt(CI2), m_Value(A))) ||
match(Op0, m_LShr(m_ConstantInt(CI2), m_Value(A)))) {
return FoldICmpCstShrCst(I, Op0, A, CI, CI2);
}
}
// If this comparison is a normal comparison, it demands all
// bits, if it is a sign bit comparison, it only demands the sign bit.
bool UnusedBit;

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@ -0,0 +1,677 @@
; RUN: opt < %s -instcombine -S | FileCheck %s
target datalayout = "e-p:64:64:64-p1:16:16:16-p2:32:32:32-p3:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
; CHECK-LABEL: @exact_lshr_eq_both_zero
; CHECK-NEXT: ret i1 true
define i1 @exact_lshr_eq_both_zero(i8 %a) {
%shr = lshr exact i8 0, %a
%cmp = icmp eq i8 %shr, 0
ret i1 %cmp
}
; CHECK-LABEL: @exact_ashr_eq_both_zero
; CHECK-NEXT: ret i1 true
define i1 @exact_ashr_eq_both_zero(i8 %a) {
%shr = ashr exact i8 0, %a
%cmp = icmp eq i8 %shr, 0
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_lshr_eq_both_zero
; CHECK-NEXT: ret i1 true
define i1 @nonexact_lshr_eq_both_zero(i8 %a) {
%shr = lshr i8 0, %a
%cmp = icmp eq i8 %shr, 0
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_ashr_eq_both_zero
; CHECK-NEXT: ret i1 true
define i1 @nonexact_ashr_eq_both_zero(i8 %a) {
%shr = ashr i8 0, %a
%cmp = icmp eq i8 %shr, 0
ret i1 %cmp
}
; CHECK-LABEL: @exact_lshr_ne_both_zero
; CHECK-NEXT: ret i1 false
define i1 @exact_lshr_ne_both_zero(i8 %a) {
%shr = lshr exact i8 0, %a
%cmp = icmp ne i8 %shr, 0
ret i1 %cmp
}
; CHECK-LABEL: @exact_ashr_ne_both_zero
; CHECK-NEXT: ret i1 false
define i1 @exact_ashr_ne_both_zero(i8 %a) {
%shr = ashr exact i8 0, %a
%cmp = icmp ne i8 %shr, 0
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_lshr_ne_both_zero
; CHECK-NEXT: ret i1 false
define i1 @nonexact_lshr_ne_both_zero(i8 %a) {
%shr = lshr i8 0, %a
%cmp = icmp ne i8 %shr, 0
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_ashr_ne_both_zero
; CHECK-NEXT: ret i1 false
define i1 @nonexact_ashr_ne_both_zero(i8 %a) {
%shr = ashr i8 0, %a
%cmp = icmp ne i8 %shr, 0
ret i1 %cmp
}
; CHECK-LABEL: @exact_lshr_eq_last_zero
; CHECK-NEXT: ret i1 false
define i1 @exact_lshr_eq_last_zero(i8 %a) {
%shr = lshr exact i8 128, %a
%cmp = icmp eq i8 %shr, 0
ret i1 %cmp
}
; CHECK-LABEL: @exact_ashr_eq_last_zero
; CHECK-NEXT: ret i1 false
define i1 @exact_ashr_eq_last_zero(i8 %a) {
%shr = ashr exact i8 -128, %a
%cmp = icmp eq i8 %shr, 0
ret i1 %cmp
}
; CHECK-LABEL: @exact_lshr_ne_last_zero
; CHECK-NEXT: ret i1 true
define i1 @exact_lshr_ne_last_zero(i8 %a) {
%shr = lshr exact i8 128, %a
%cmp = icmp ne i8 %shr, 0
ret i1 %cmp
}
; CHECK-LABEL: @exact_ashr_ne_last_zero
; CHECK-NEXT: ret i1 true
define i1 @exact_ashr_ne_last_zero(i8 %a) {
%shr = ashr exact i8 -128, %a
%cmp = icmp ne i8 %shr, 0
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_lshr_eq_last_zero
; CHECK-NEXT: ret i1 false
define i1 @nonexact_lshr_eq_last_zero(i8 %a) {
%shr = lshr i8 128, %a
%cmp = icmp eq i8 %shr, 0
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_ashr_eq_last_zero
; CHECK-NEXT: ret i1 false
define i1 @nonexact_ashr_eq_last_zero(i8 %a) {
%shr = ashr i8 -128, %a
%cmp = icmp eq i8 %shr, 0
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_lshr_ne_last_zero
; CHECK-NEXT: ret i1 true
define i1 @nonexact_lshr_ne_last_zero(i8 %a) {
%shr = lshr i8 128, %a
%cmp = icmp ne i8 %shr, 0
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_ashr_ne_last_zero
; CHECK-NEXT: ret i1 true
define i1 @nonexact_ashr_ne_last_zero(i8 %a) {
%shr = ashr i8 -128, %a
%cmp = icmp ne i8 %shr, 0
ret i1 %cmp
}
; CHECK-LABEL: @lshr_eq_msb_low_last_zero
; CHECK-NEXT: icmp ugt i8 %a, 6
define i1 @lshr_eq_msb_low_last_zero(i8 %a) {
%shr = lshr i8 127, %a
%cmp = icmp eq i8 %shr, 0
ret i1 %cmp
}
; CHECK-LABEL: @ashr_eq_msb_low_second_zero
; CHECK-NEXT: icmp ugt i8 %a, 6
define i1 @ashr_eq_msb_low_second_zero(i8 %a) {
%shr = ashr i8 127, %a
%cmp = icmp eq i8 %shr, 0
ret i1 %cmp
}
; CHECK-LABEL: @lshr_ne_msb_low_last_zero
; CHECK-NEXT: icmp ult i8 %a, 7
define i1 @lshr_ne_msb_low_last_zero(i8 %a) {
%shr = lshr i8 127, %a
%cmp = icmp ne i8 %shr, 0
ret i1 %cmp
}
; CHECK-LABEL: @ashr_ne_msb_low_second_zero
; CHECK-NEXT: icmp ult i8 %a, 7
define i1 @ashr_ne_msb_low_second_zero(i8 %a) {
%shr = ashr i8 127, %a
%cmp = icmp ne i8 %shr, 0
ret i1 %cmp
}
; CHECK-LABEL: @lshr_eq_first_zero
; CHECK-NEXT: ret i1 false
define i1 @lshr_eq_first_zero(i8 %a) {
%shr = lshr i8 0, %a
%cmp = icmp eq i8 %shr, 2
ret i1 %cmp
}
; CHECK-LABEL: @ashr_eq_first_zero
; CHECK-NEXT: ret i1 false
define i1 @ashr_eq_first_zero(i8 %a) {
%shr = ashr i8 0, %a
%cmp = icmp eq i8 %shr, 2
ret i1 %cmp
}
; CHECK-LABEL: @lshr_ne_first_zero
; CHECK-NEXT: ret i1 true
define i1 @lshr_ne_first_zero(i8 %a) {
%shr = lshr i8 0, %a
%cmp = icmp ne i8 %shr, 2
ret i1 %cmp
}
; CHECK-LABEL: @ashr_ne_first_zero
; CHECK-NEXT: ret i1 true
define i1 @ashr_ne_first_zero(i8 %a) {
%shr = ashr i8 0, %a
%cmp = icmp ne i8 %shr, 2
ret i1 %cmp
}
; CHECK-LABEL: @ashr_eq_both_minus1
; CHECK-NEXT: ret i1 true
define i1 @ashr_eq_both_minus1(i8 %a) {
%shr = ashr i8 -1, %a
%cmp = icmp eq i8 %shr, -1
ret i1 %cmp
}
; CHECK-LABEL: @ashr_ne_both_minus1
; CHECK-NEXT: ret i1 false
define i1 @ashr_ne_both_minus1(i8 %a) {
%shr = ashr i8 -1, %a
%cmp = icmp ne i8 %shr, -1
ret i1 %cmp
}
; CHECK-LABEL: @exact_ashr_eq_both_minus1
; CHECK-NEXT: ret i1 true
define i1 @exact_ashr_eq_both_minus1(i8 %a) {
%shr = ashr exact i8 -1, %a
%cmp = icmp eq i8 %shr, -1
ret i1 %cmp
}
; CHECK-LABEL: @exact_ashr_ne_both_minus1
; CHECK-NEXT: ret i1 false
define i1 @exact_ashr_ne_both_minus1(i8 %a) {
%shr = ashr exact i8 -1, %a
%cmp = icmp ne i8 %shr, -1
ret i1 %cmp
}
; CHECK-LABEL: @ashr_eq_both_equal
; CHECK-NEXT: icmp eq i8 %a, 0
define i1 @ashr_eq_both_equal(i8 %a) {
%shr = ashr i8 128, %a
%cmp = icmp eq i8 %shr, 128
ret i1 %cmp
}
; CHECK-LABEL: @ashr_ne_both_equal
; CHECK-NEXT: icmp ne i8 %a, 0
define i1 @ashr_ne_both_equal(i8 %a) {
%shr = ashr i8 128, %a
%cmp = icmp ne i8 %shr, 128
ret i1 %cmp
}
; CHECK-LABEL: @lshr_eq_both_equal
; CHECK-NEXT: icmp eq i8 %a, 0
define i1 @lshr_eq_both_equal(i8 %a) {
%shr = lshr i8 127, %a
%cmp = icmp eq i8 %shr, 127
ret i1 %cmp
}
; CHECK-LABEL: @lshr_ne_both_equal
; CHECK-NEXT: icmp ne i8 %a, 0
define i1 @lshr_ne_both_equal(i8 %a) {
%shr = lshr i8 127, %a
%cmp = icmp ne i8 %shr, 127
ret i1 %cmp
}
; CHECK-LABEL: @exact_ashr_eq_both_equal
; CHECK-NEXT: icmp eq i8 %a, 0
define i1 @exact_ashr_eq_both_equal(i8 %a) {
%shr = ashr exact i8 128, %a
%cmp = icmp eq i8 %shr, 128
ret i1 %cmp
}
; CHECK-LABEL: @exact_ashr_ne_both_equal
; CHECK-NEXT: icmp ne i8 %a, 0
define i1 @exact_ashr_ne_both_equal(i8 %a) {
%shr = ashr exact i8 128, %a
%cmp = icmp ne i8 %shr, 128
ret i1 %cmp
}
; CHECK-LABEL: @exact_lshr_eq_both_equal
; CHECK-NEXT: icmp eq i8 %a, 0
define i1 @exact_lshr_eq_both_equal(i8 %a) {
%shr = lshr exact i8 126, %a
%cmp = icmp eq i8 %shr, 126
ret i1 %cmp
}
; CHECK-LABEL: @exact_lshr_ne_both_equal
; CHECK-NEXT: icmp ne i8 %a, 0
define i1 @exact_lshr_ne_both_equal(i8 %a) {
%shr = lshr exact i8 126, %a
%cmp = icmp ne i8 %shr, 126
ret i1 %cmp
}
; CHECK-LABEL: @exact_ashr_eq_opposite_msb
; CHECK-NEXT: ret i1 false
define i1 @exact_ashr_eq_opposite_msb(i8 %a) {
%shr = ashr exact i8 -128, %a
%cmp = icmp eq i8 %shr, 1
ret i1 %cmp
}
; CHECK-LABEL: @ashr_eq_opposite_msb
; CHECK-NEXT: ret i1 false
define i1 @ashr_eq_opposite_msb(i8 %a) {
%shr = ashr i8 -128, %a
%cmp = icmp eq i8 %shr, 1
ret i1 %cmp
}
; CHECK-LABEL: @exact_lshr_eq_opposite_msb
; CHECK-NEXT: icmp eq i8 %a, 7
define i1 @exact_lshr_eq_opposite_msb(i8 %a) {
%shr = lshr exact i8 -128, %a
%cmp = icmp eq i8 %shr, 1
ret i1 %cmp
}
; CHECK-LABEL: @lshr_eq_opposite_msb
; CHECK-NEXT: icmp eq i8 %a, 7
define i1 @lshr_eq_opposite_msb(i8 %a) {
%shr = lshr i8 -128, %a
%cmp = icmp eq i8 %shr, 1
ret i1 %cmp
}
; CHECK-LABEL: @exact_ashr_ne_opposite_msb
; CHECK-NEXT: ret i1 true
define i1 @exact_ashr_ne_opposite_msb(i8 %a) {
%shr = ashr exact i8 -128, %a
%cmp = icmp ne i8 %shr, 1
ret i1 %cmp
}
; CHECK-LABEL: @ashr_ne_opposite_msb
; CHECK-NEXT: ret i1 true
define i1 @ashr_ne_opposite_msb(i8 %a) {
%shr = ashr i8 -128, %a
%cmp = icmp ne i8 %shr, 1
ret i1 %cmp
}
; CHECK-LABEL: @exact_lshr_ne_opposite_msb
; CHECK-NEXT: icmp ne i8 %a, 7
define i1 @exact_lshr_ne_opposite_msb(i8 %a) {
%shr = lshr exact i8 -128, %a
%cmp = icmp ne i8 %shr, 1
ret i1 %cmp
}
; CHECK-LABEL: @lshr_ne_opposite_msb
; CHECK-NEXT: icmp ne i8 %a, 7
define i1 @lshr_ne_opposite_msb(i8 %a) {
%shr = lshr i8 -128, %a
%cmp = icmp ne i8 %shr, 1
ret i1 %cmp
}
; CHECK-LABEL: @exact_ashr_eq_shift_gt
; CHECK-NEXT : ret i1 false
define i1 @exact_ashr_eq_shift_gt(i8 %a) {
%shr = ashr exact i8 -2, %a
%cmp = icmp eq i8 %shr, -8
ret i1 %cmp
}
; CHECK-LABEL: @exact_ashr_ne_shift_gt
; CHECK-NEXT : ret i1 true
define i1 @exact_ashr_ne_shift_gt(i8 %a) {
%shr = ashr exact i8 -2, %a
%cmp = icmp ne i8 %shr, -8
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_ashr_eq_shift_gt
; CHECK-NEXT : ret i1 false
define i1 @nonexact_ashr_eq_shift_gt(i8 %a) {
%shr = ashr i8 -2, %a
%cmp = icmp eq i8 %shr, -8
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_ashr_ne_shift_gt
; CHECK-NEXT : ret i1 true
define i1 @nonexact_ashr_ne_shift_gt(i8 %a) {
%shr = ashr i8 -2, %a
%cmp = icmp ne i8 %shr, -8
ret i1 %cmp
}
; CHECK-LABEL: @exact_lshr_eq_shift_gt
; CHECK-NEXT: ret i1 false
define i1 @exact_lshr_eq_shift_gt(i8 %a) {
%shr = lshr exact i8 2, %a
%cmp = icmp eq i8 %shr, 8
ret i1 %cmp
}
; CHECK-LABEL: @exact_lshr_ne_shift_gt
; CHECK-NEXT: ret i1 true
define i1 @exact_lshr_ne_shift_gt(i8 %a) {
%shr = lshr exact i8 2, %a
%cmp = icmp ne i8 %shr, 8
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_lshr_eq_shift_gt
; CHECK-NEXT : ret i1 false
define i1 @nonexact_lshr_eq_shift_gt(i8 %a) {
%shr = lshr i8 2, %a
%cmp = icmp eq i8 %shr, 8
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_lshr_ne_shift_gt
; CHECK-NEXT : ret i1 true
define i1 @nonexact_lshr_ne_shift_gt(i8 %a) {
%shr = ashr i8 2, %a
%cmp = icmp ne i8 %shr, 8
ret i1 %cmp
}
; CHECK-LABEL: @exact_ashr_eq
; CHECK-NEXT: icmp eq i8 %a, 7
define i1 @exact_ashr_eq(i8 %a) {
%shr = ashr exact i8 -128, %a
%cmp = icmp eq i8 %shr, -1
ret i1 %cmp
}
; CHECK-LABEL: @exact_ashr_ne
; CHECK-NEXT: icmp ne i8 %a, 7
define i1 @exact_ashr_ne(i8 %a) {
%shr = ashr exact i8 -128, %a
%cmp = icmp ne i8 %shr, -1
ret i1 %cmp
}
; CHECK-LABEL: @exact_lshr_eq
; CHECK-NEXT: icmp eq i8 %a, 2
define i1 @exact_lshr_eq(i8 %a) {
%shr = lshr exact i8 4, %a
%cmp = icmp eq i8 %shr, 1
ret i1 %cmp
}
; CHECK-LABEL: @exact_lshr_ne
; CHECK-NEXT: icmp ne i8 %a, 2
define i1 @exact_lshr_ne(i8 %a) {
%shr = lshr exact i8 4, %a
%cmp = icmp ne i8 %shr, 1
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_ashr_eq
; CHECK-NEXT: icmp eq i8 %a, 7
define i1 @nonexact_ashr_eq(i8 %a) {
%shr = ashr i8 -128, %a
%cmp = icmp eq i8 %shr, -1
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_ashr_ne
; CHECK-NEXT: icmp ne i8 %a, 7
define i1 @nonexact_ashr_ne(i8 %a) {
%shr = ashr i8 -128, %a
%cmp = icmp ne i8 %shr, -1
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_lshr_eq
; CHECK-NEXT: icmp eq i8 %a, 2
define i1 @nonexact_lshr_eq(i8 %a) {
%shr = lshr i8 4, %a
%cmp = icmp eq i8 %shr, 1
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_lshr_ne
; CHECK-NEXT: icmp ne i8 %a, 2
define i1 @nonexact_lshr_ne(i8 %a) {
%shr = lshr i8 4, %a
%cmp = icmp ne i8 %shr, 1
ret i1 %cmp
}
; CHECK-LABEL: @exact_lshr_eq_exactdiv
; CHECK-NEXT: icmp eq i8 %a, 4
define i1 @exact_lshr_eq_exactdiv(i8 %a) {
%shr = lshr exact i8 80, %a
%cmp = icmp eq i8 %shr, 5
ret i1 %cmp
}
; CHECK-LABEL: @exact_lshr_ne_exactdiv
; CHECK-NEXT: icmp ne i8 %a, 4
define i1 @exact_lshr_ne_exactdiv(i8 %a) {
%shr = lshr exact i8 80, %a
%cmp = icmp ne i8 %shr, 5
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_lshr_eq_exactdiv
; CHECK-NEXT: icmp eq i8 %a, 4
define i1 @nonexact_lshr_eq_exactdiv(i8 %a) {
%shr = lshr i8 80, %a
%cmp = icmp eq i8 %shr, 5
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_lshr_ne_exactdiv
; CHECK-NEXT: icmp ne i8 %a, 4
define i1 @nonexact_lshr_ne_exactdiv(i8 %a) {
%shr = lshr i8 80, %a
%cmp = icmp ne i8 %shr, 5
ret i1 %cmp
}
; CHECK-LABEL: @exact_ashr_eq_exactdiv
; CHECK-NEXT: icmp eq i8 %a, 4
define i1 @exact_ashr_eq_exactdiv(i8 %a) {
%shr = ashr exact i8 -80, %a
%cmp = icmp eq i8 %shr, -5
ret i1 %cmp
}
; CHECK-LABEL: @exact_ashr_ne_exactdiv
; CHECK-NEXT: icmp ne i8 %a, 4
define i1 @exact_ashr_ne_exactdiv(i8 %a) {
%shr = ashr exact i8 -80, %a
%cmp = icmp ne i8 %shr, -5
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_ashr_eq_exactdiv
; CHECK-NEXT: icmp eq i8 %a, 4
define i1 @nonexact_ashr_eq_exactdiv(i8 %a) {
%shr = ashr i8 -80, %a
%cmp = icmp eq i8 %shr, -5
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_ashr_ne_exactdiv
; CHECK-NEXT: icmp ne i8 %a, 4
define i1 @nonexact_ashr_ne_exactdiv(i8 %a) {
%shr = ashr i8 -80, %a
%cmp = icmp ne i8 %shr, -5
ret i1 %cmp
}
; CHECK-LABEL: @exact_lshr_eq_noexactdiv
; CHECK-NEXT: ret i1 false
define i1 @exact_lshr_eq_noexactdiv(i8 %a) {
%shr = lshr exact i8 80, %a
%cmp = icmp eq i8 %shr, 31
ret i1 %cmp
}
; CHECK-LABEL: @exact_lshr_ne_noexactdiv
; CHECK-NEXT: ret i1 true
define i1 @exact_lshr_ne_noexactdiv(i8 %a) {
%shr = lshr exact i8 80, %a
%cmp = icmp ne i8 %shr, 31
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_lshr_eq_noexactdiv
; CHECK-NEXT: ret i1 false
define i1 @nonexact_lshr_eq_noexactdiv(i8 %a) {
%shr = lshr i8 80, %a
%cmp = icmp eq i8 %shr, 31
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_lshr_ne_noexactdiv
; CHECK-NEXT: ret i1 true
define i1 @nonexact_lshr_ne_noexactdiv(i8 %a) {
%shr = lshr i8 80, %a
%cmp = icmp ne i8 %shr, 31
ret i1 %cmp
}
; CHECK-LABEL: @exact_ashr_eq_noexactdiv
; CHECK-NEXT: ret i1 false
define i1 @exact_ashr_eq_noexactdiv(i8 %a) {
%shr = ashr exact i8 -80, %a
%cmp = icmp eq i8 %shr, -31
ret i1 %cmp
}
; CHECK-LABEL: @exact_ashr_ne_noexactdiv
; CHECK-NEXT: ret i1 true
define i1 @exact_ashr_ne_noexactdiv(i8 %a) {
%shr = ashr exact i8 -80, %a
%cmp = icmp ne i8 %shr, -31
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_ashr_eq_noexactdiv
; CHECK-NEXT: ret i1 false
define i1 @nonexact_ashr_eq_noexactdiv(i8 %a) {
%shr = ashr i8 -80, %a
%cmp = icmp eq i8 %shr, -31
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_ashr_ne_noexactdiv
; CHECK-NEXT: ret i1 true
define i1 @nonexact_ashr_ne_noexactdiv(i8 %a) {
%shr = ashr i8 -80, %a
%cmp = icmp ne i8 %shr, -31
ret i1 %cmp
}
; CHECK-LABEL: @exact_lshr_eq_noexactlog
; CHECK-NEXT: ret i1 false
define i1 @exact_lshr_eq_noexactlog(i8 %a) {
%shr = lshr exact i8 90, %a
%cmp = icmp eq i8 %shr, 30
ret i1 %cmp
}
; CHECK-LABEL: @exact_lshr_ne_noexactlog
; CHECK-NEXT: ret i1 true
define i1 @exact_lshr_ne_noexactlog(i8 %a) {
%shr = lshr exact i8 90, %a
%cmp = icmp ne i8 %shr, 30
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_lshr_eq_noexactlog
; CHECK-NEXT: ret i1 false
define i1 @nonexact_lshr_eq_noexactlog(i8 %a) {
%shr = lshr i8 90, %a
%cmp = icmp eq i8 %shr, 30
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_lshr_ne_noexactlog
; CHECK-NEXT: ret i1 true
define i1 @nonexact_lshr_ne_noexactlog(i8 %a) {
%shr = lshr i8 90, %a
%cmp = icmp ne i8 %shr, 30
ret i1 %cmp
}
; CHECK-LABEL: @exact_ashr_eq_noexactlog
; CHECK-NEXT: ret i1 false
define i1 @exact_ashr_eq_noexactlog(i8 %a) {
%shr = ashr exact i8 -90, %a
%cmp = icmp eq i8 %shr, -30
ret i1 %cmp
}
; CHECK-LABEL: @exact_ashr_ne_noexactlog
; CHECK-NEXT: ret i1 true
define i1 @exact_ashr_ne_noexactlog(i8 %a) {
%shr = ashr exact i8 -90, %a
%cmp = icmp ne i8 %shr, -30
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_ashr_eq_noexactlog
; CHECK-NEXT: ret i1 false
define i1 @nonexact_ashr_eq_noexactlog(i8 %a) {
%shr = ashr i8 -90, %a
%cmp = icmp eq i8 %shr, -30
ret i1 %cmp
}
; CHECK-LABEL: @nonexact_ashr_ne_noexactlog
; CHECK-NEXT: ret i1 true
define i1 @nonexact_ashr_ne_noexactlog(i8 %a) {
%shr = ashr i8 -90, %a
%cmp = icmp ne i8 %shr, -30
ret i1 %cmp
}