RPCS3/llvm-mirror
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2025-01-31 20:51:52 +01:00
Code Issues Projects Releases Wiki Activity

[InstCombine] factorize left shifts of add/sub

Browse Source 
We do similar factorization folds in SimplifyUsingDistributiveLaws,
but that drops no-wrap properties. Propagating those optimally may
help solve:
https://llvm.org/PR47430

The propagation is all-or-nothing for these patterns: when all
3 incoming ops have nsw or nuw, the 2 new ops should have the
same no-wrap property:
https://alive2.llvm.org/ce/z/Dv8wsU

This also solves:
https://llvm.org/PR47584
This commit is contained in:
Sanjay Patel 2020-09-20 12:55:24 -04:00
parent 2991bca580
commit 79a8f1c79c
2 changed files with 80 additions and 52 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

42
lib/Transforms/InstCombine/InstCombineAddSub.cpp
View File

@ -1199,6 +1199,42 @@ Instruction *InstCombinerImpl::
return TruncInst::CreateTruncOrBitCast(NewAShr, I.getType());
}
/// This is a specialization of a more general transform from
/// SimplifyUsingDistributiveLaws. If that code can be made to work optimally
/// for multi-use cases or propagating nsw/nuw, then we would not need this.
static Instruction *factorizeMathWithShlOps(BinaryOperator &I,
InstCombiner::BuilderTy &Builder) {
// TODO: Also handle mul by doubling the shift amount?
assert(I.getOpcode() == Instruction::Add ||
I.getOpcode() == Instruction::Sub && "Expected add/sub");
auto *Op0 = dyn_cast<BinaryOperator>(I.getOperand(0));
auto *Op1 = dyn_cast<BinaryOperator>(I.getOperand(1));
if (!Op0 || !Op1 || !(Op0->hasOneUse() || Op1->hasOneUse()))
return nullptr;
Value *X, *Y, *ShAmt;
if (!match(Op0, m_Shl(m_Value(X), m_Value(ShAmt))) ||
!match(Op1, m_Shl(m_Value(Y), m_Specific(ShAmt))))
return nullptr;
// No-wrap propagates only when all ops have no-wrap.
bool HasNSW = I.hasNoSignedWrap() && Op0->hasNoSignedWrap() &&
Op1->hasNoSignedWrap();
bool HasNUW = I.hasNoUnsignedWrap() && Op0->hasNoUnsignedWrap() &&
Op1->hasNoUnsignedWrap();
// add/sub (X << ShAmt), (Y << ShAmt) --> (add/sub X, Y) << ShAmt
Value *NewMath = Builder.CreateBinOp(I.getOpcode(), X, Y);
if (auto *NewI = dyn_cast<BinaryOperator>(NewMath)) {
NewI->setHasNoSignedWrap(HasNSW);
NewI->setHasNoUnsignedWrap(HasNUW);
}
auto *NewShl = BinaryOperator::CreateShl(NewMath, ShAmt);
NewShl->setHasNoSignedWrap(HasNSW);
NewShl->setHasNoUnsignedWrap(HasNUW);
return NewShl;
}
Instruction *InstCombinerImpl::visitAdd(BinaryOperator &I) {
if (Value *V = SimplifyAddInst(I.getOperand(0), I.getOperand(1),
I.hasNoSignedWrap(), I.hasNoUnsignedWrap(),
@ -1215,6 +1251,9 @@ Instruction *InstCombinerImpl::visitAdd(BinaryOperator &I) {
if (Value *V = SimplifyUsingDistributiveLaws(I))
return replaceInstUsesWith(I, V);
if (Instruction *R = factorizeMathWithShlOps(I, Builder))
return R;
if (Instruction *X = foldAddWithConstant(I))
return X;
@ -1753,6 +1792,9 @@ Instruction *InstCombinerImpl::visitSub(BinaryOperator &I) {
if (Value *V = SimplifyUsingDistributiveLaws(I))
return replaceInstUsesWith(I, V);
if (Instruction *R = factorizeMathWithShlOps(I, Builder))
return R;
if (I.getType()->isIntOrIntVectorTy(1))
return BinaryOperator::CreateXor(Op0, Op1);

90
test/Transforms/InstCombine/shl-factor.ll
View File

@ -5,9 +5,8 @@ declare void @use8(i8)
define i6 @add_shl_same_amount(i6 %x, i6 %y, i6 %z) {
; CHECK-LABEL: @add_shl_same_amount(
; CHECK-NEXT: [[XS:%.*]] = shl i6 [[X:%.*]], [[Z:%.*]]
; CHECK-NEXT: [[YS:%.*]] = shl i6 [[Y:%.*]], [[Z]]
; CHECK-NEXT: [[DIFF:%.*]] = add i6 [[XS]], [[YS]]
; CHECK-NEXT: [[TMP1:%.*]] = add i6 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[DIFF:%.*]] = shl i6 [[TMP1]], [[Z:%.*]]
; CHECK-NEXT: ret i6 [[DIFF]]
;
%xs = shl i6 %x, %z
@ -18,9 +17,8 @@ define i6 @add_shl_same_amount(i6 %x, i6 %y, i6 %z) {
define <2 x i4> @add_shl_same_amount_nsw(<2 x i4> %x, <2 x i4> %y, <2 x i4> %z) {
; CHECK-LABEL: @add_shl_same_amount_nsw(
; CHECK-NEXT: [[XS:%.*]] = shl nsw <2 x i4> [[X:%.*]], [[Z:%.*]]
; CHECK-NEXT: [[YS:%.*]] = shl nsw <2 x i4> [[Y:%.*]], [[Z]]
; CHECK-NEXT: [[DIFF:%.*]] = add nsw <2 x i4> [[XS]], [[YS]]
; CHECK-NEXT: [[TMP1:%.*]] = add nsw <2 x i4> [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[DIFF:%.*]] = shl nsw <2 x i4> [[TMP1]], [[Z:%.*]]
; CHECK-NEXT: ret <2 x i4> [[DIFF]]
;
%xs = shl nsw <2 x i4> %x, %z
@ -31,9 +29,8 @@ define <2 x i4> @add_shl_same_amount_nsw(<2 x i4> %x, <2 x i4> %y, <2 x i4> %z)
define i64 @add_shl_same_amount_nuw(i64 %x, i64 %y, i64 %z) {
; CHECK-LABEL: @add_shl_same_amount_nuw(
; CHECK-NEXT: [[XS:%.*]] = shl nuw i64 [[X:%.*]], [[Z:%.*]]
; CHECK-NEXT: [[YS:%.*]] = shl nuw i64 [[Y:%.*]], [[Z]]
; CHECK-NEXT: [[DIFF:%.*]] = add nuw i64 [[XS]], [[YS]]
; CHECK-NEXT: [[TMP1:%.*]] = add nuw i64 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[DIFF:%.*]] = shl nuw i64 [[TMP1]], [[Z:%.*]]
; CHECK-NEXT: ret i64 [[DIFF]]
;
%xs = shl nuw i64 %x, %z
@ -46,8 +43,8 @@ define i8 @add_shl_same_amount_nsw_extra_use1(i8 %x, i8 %y, i8 %z) {
; CHECK-LABEL: @add_shl_same_amount_nsw_extra_use1(
; CHECK-NEXT: [[XS:%.*]] = shl nuw nsw i8 [[X:%.*]], [[Z:%.*]]
; CHECK-NEXT: call void @use8(i8 [[XS]])
; CHECK-NEXT: [[YS:%.*]] = shl nuw nsw i8 [[Y:%.*]], [[Z]]
; CHECK-NEXT: [[DIFF:%.*]] = add nsw i8 [[XS]], [[YS]]
; CHECK-NEXT: [[TMP1:%.*]] = add nsw i8 [[X]], [[Y:%.*]]
; CHECK-NEXT: [[DIFF:%.*]] = shl nsw i8 [[TMP1]], [[Z]]
; CHECK-NEXT: ret i8 [[DIFF]]
;
%xs = shl nsw nuw i8 %x, %z
@ -59,10 +56,10 @@ define i8 @add_shl_same_amount_nsw_extra_use1(i8 %x, i8 %y, i8 %z) {
define i8 @add_shl_same_amount_nuw_extra_use2(i8 %x, i8 %y, i8 %z) {
; CHECK-LABEL: @add_shl_same_amount_nuw_extra_use2(
; CHECK-NEXT: [[XS:%.*]] = shl nuw i8 [[X:%.*]], [[Z:%.*]]
; CHECK-NEXT: [[YS:%.*]] = shl nuw nsw i8 [[Y:%.*]], [[Z]]
; CHECK-NEXT: [[YS:%.*]] = shl nuw nsw i8 [[Y:%.*]], [[Z:%.*]]
; CHECK-NEXT: call void @use8(i8 [[YS]])
; CHECK-NEXT: [[DIFF:%.*]] = add nuw nsw i8 [[XS]], [[YS]]
; CHECK-NEXT: [[TMP1:%.*]] = add nuw i8 [[X:%.*]], [[Y]]
; CHECK-NEXT: [[DIFF:%.*]] = shl nuw i8 [[TMP1]], [[Z]]
; CHECK-NEXT: ret i8 [[DIFF]]
;
%xs = shl nuw i8 %x, %z
@ -91,9 +88,8 @@ define i8 @add_shl_same_amount_nsw_nuw_extra_use3(i8 %x, i8 %y, i8 %z) {
define i6 @add_shl_same_amount_partial_nsw1(i6 %x, i6 %y, i6 %z) {
; CHECK-LABEL: @add_shl_same_amount_partial_nsw1(
; CHECK-NEXT: [[XS:%.*]] = shl nsw i6 [[X:%.*]], [[Z:%.*]]
; CHECK-NEXT: [[YS:%.*]] = shl nsw i6 [[Y:%.*]], [[Z]]
; CHECK-NEXT: [[DIFF:%.*]] = add i6 [[XS]], [[YS]]
; CHECK-NEXT: [[TMP1:%.*]] = add i6 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[DIFF:%.*]] = shl i6 [[TMP1]], [[Z:%.*]]
; CHECK-NEXT: ret i6 [[DIFF]]
;
%xs = shl nsw i6 %x, %z
@ -104,9 +100,8 @@ define i6 @add_shl_same_amount_partial_nsw1(i6 %x, i6 %y, i6 %z) {
define i6 @add_shl_same_amount_partial_nsw2(i6 %x, i6 %y, i6 %z) {
; CHECK-LABEL: @add_shl_same_amount_partial_nsw2(
; CHECK-NEXT: [[XS:%.*]] = shl i6 [[X:%.*]], [[Z:%.*]]
; CHECK-NEXT: [[YS:%.*]] = shl nsw i6 [[Y:%.*]], [[Z]]
; CHECK-NEXT: [[DIFF:%.*]] = add nsw i6 [[XS]], [[YS]]
; CHECK-NEXT: [[TMP1:%.*]] = add i6 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[DIFF:%.*]] = shl i6 [[TMP1]], [[Z:%.*]]
; CHECK-NEXT: ret i6 [[DIFF]]
;
%xs = shl i6 %x, %z
@ -117,9 +112,8 @@ define i6 @add_shl_same_amount_partial_nsw2(i6 %x, i6 %y, i6 %z) {
define i6 @add_shl_same_amount_partial_nuw1(i6 %x, i6 %y, i6 %z) {
; CHECK-LABEL: @add_shl_same_amount_partial_nuw1(
; CHECK-NEXT: [[XS:%.*]] = shl nuw i6 [[X:%.*]], [[Z:%.*]]
; CHECK-NEXT: [[YS:%.*]] = shl nuw i6 [[Y:%.*]], [[Z]]
; CHECK-NEXT: [[DIFF:%.*]] = add i6 [[XS]], [[YS]]
; CHECK-NEXT: [[TMP1:%.*]] = add i6 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[DIFF:%.*]] = shl i6 [[TMP1]], [[Z:%.*]]
; CHECK-NEXT: ret i6 [[DIFF]]
;
%xs = shl nuw i6 %x, %z
@ -130,9 +124,8 @@ define i6 @add_shl_same_amount_partial_nuw1(i6 %x, i6 %y, i6 %z) {
define i6 @add_shl_same_amount_partial_nuw2(i6 %x, i6 %y, i6 %z) {
; CHECK-LABEL: @add_shl_same_amount_partial_nuw2(
; CHECK-NEXT: [[XS:%.*]] = shl nuw i6 [[X:%.*]], [[Z:%.*]]
; CHECK-NEXT: [[YS:%.*]] = shl i6 [[Y:%.*]], [[Z]]
; CHECK-NEXT: [[DIFF:%.*]] = add nuw i6 [[XS]], [[YS]]
; CHECK-NEXT: [[TMP1:%.*]] = add i6 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[DIFF:%.*]] = shl i6 [[TMP1]], [[Z:%.*]]
; CHECK-NEXT: ret i6 [[DIFF]]
;
%xs = shl nuw i6 %x, %z
@ -143,9 +136,8 @@ define i6 @add_shl_same_amount_partial_nuw2(i6 %x, i6 %y, i6 %z) {
define i6 @sub_shl_same_amount(i6 %x, i6 %y, i6 %z) {
; CHECK-LABEL: @sub_shl_same_amount(
; CHECK-NEXT: [[XS:%.*]] = shl i6 [[X:%.*]], [[Z:%.*]]
; CHECK-NEXT: [[YS:%.*]] = shl i6 [[Y:%.*]], [[Z]]
; CHECK-NEXT: [[DIFF:%.*]] = sub i6 [[XS]], [[YS]]
; CHECK-NEXT: [[TMP1:%.*]] = sub i6 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[DIFF:%.*]] = shl i6 [[TMP1]], [[Z:%.*]]
; CHECK-NEXT: ret i6 [[DIFF]]
;
%xs = shl i6 %x, %z
@ -156,9 +148,8 @@ define i6 @sub_shl_same_amount(i6 %x, i6 %y, i6 %z) {
define <2 x i4> @sub_shl_same_amount_nsw(<2 x i4> %x, <2 x i4> %y, <2 x i4> %z) {
; CHECK-LABEL: @sub_shl_same_amount_nsw(
; CHECK-NEXT: [[XS:%.*]] = shl nsw <2 x i4> [[X:%.*]], [[Z:%.*]]
; CHECK-NEXT: [[YS:%.*]] = shl nsw <2 x i4> [[Y:%.*]], [[Z]]
; CHECK-NEXT: [[DIFF:%.*]] = sub nsw <2 x i4> [[XS]], [[YS]]
; CHECK-NEXT: [[TMP1:%.*]] = sub nsw <2 x i4> [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[DIFF:%.*]] = shl nsw <2 x i4> [[TMP1]], [[Z:%.*]]
; CHECK-NEXT: ret <2 x i4> [[DIFF]]
;
%xs = shl nsw <2 x i4> %x, %z
@ -169,9 +160,8 @@ define <2 x i4> @sub_shl_same_amount_nsw(<2 x i4> %x, <2 x i4> %y, <2 x i4> %z)
define i64 @sub_shl_same_amount_nuw(i64 %x, i64 %y, i64 %z) {
; CHECK-LABEL: @sub_shl_same_amount_nuw(
; CHECK-NEXT: [[XS:%.*]] = shl nuw i64 [[X:%.*]], [[Z:%.*]]
; CHECK-NEXT: [[YS:%.*]] = shl nuw i64 [[Y:%.*]], [[Z]]
; CHECK-NEXT: [[DIFF:%.*]] = sub nuw i64 [[XS]], [[YS]]
; CHECK-NEXT: [[TMP1:%.*]] = sub nuw i64 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[DIFF:%.*]] = shl nuw i64 [[TMP1]], [[Z:%.*]]
; CHECK-NEXT: ret i64 [[DIFF]]
;
%xs = shl nuw i64 %x, %z
@ -184,8 +174,8 @@ define i8 @sub_shl_same_amount_nsw_extra_use1(i8 %x, i8 %y, i8 %z) {
; CHECK-LABEL: @sub_shl_same_amount_nsw_extra_use1(
; CHECK-NEXT: [[XS:%.*]] = shl nuw nsw i8 [[X:%.*]], [[Z:%.*]]
; CHECK-NEXT: call void @use8(i8 [[XS]])
; CHECK-NEXT: [[YS:%.*]] = shl nuw nsw i8 [[Y:%.*]], [[Z]]
; CHECK-NEXT: [[DIFF:%.*]] = sub nsw i8 [[XS]], [[YS]]
; CHECK-NEXT: [[TMP1:%.*]] = sub nsw i8 [[X]], [[Y:%.*]]
; CHECK-NEXT: [[DIFF:%.*]] = shl nsw i8 [[TMP1]], [[Z]]
; CHECK-NEXT: ret i8 [[DIFF]]
;
%xs = shl nsw nuw i8 %x, %z
@ -197,10 +187,10 @@ define i8 @sub_shl_same_amount_nsw_extra_use1(i8 %x, i8 %y, i8 %z) {
define i8 @sub_shl_same_amount_nuw_extra_use2(i8 %x, i8 %y, i8 %z) {
; CHECK-LABEL: @sub_shl_same_amount_nuw_extra_use2(
; CHECK-NEXT: [[XS:%.*]] = shl nuw i8 [[X:%.*]], [[Z:%.*]]
; CHECK-NEXT: [[YS:%.*]] = shl nuw nsw i8 [[Y:%.*]], [[Z]]
; CHECK-NEXT: [[YS:%.*]] = shl nuw nsw i8 [[Y:%.*]], [[Z:%.*]]
; CHECK-NEXT: call void @use8(i8 [[YS]])
; CHECK-NEXT: [[DIFF:%.*]] = sub nuw nsw i8 [[XS]], [[YS]]
; CHECK-NEXT: [[TMP1:%.*]] = sub nuw i8 [[X:%.*]], [[Y]]
; CHECK-NEXT: [[DIFF:%.*]] = shl nuw i8 [[TMP1]], [[Z]]
; CHECK-NEXT: ret i8 [[DIFF]]
;
%xs = shl nuw i8 %x, %z
@ -229,9 +219,8 @@ define i8 @sub_shl_same_amount_nsw_nuw_extra_use3(i8 %x, i8 %y, i8 %z) {
define i6 @sub_shl_same_amount_partial_nsw1(i6 %x, i6 %y, i6 %z) {
; CHECK-LABEL: @sub_shl_same_amount_partial_nsw1(
; CHECK-NEXT: [[XS:%.*]] = shl nsw i6 [[X:%.*]], [[Z:%.*]]
; CHECK-NEXT: [[YS:%.*]] = shl nsw i6 [[Y:%.*]], [[Z]]
; CHECK-NEXT: [[DIFF:%.*]] = sub i6 [[XS]], [[YS]]
; CHECK-NEXT: [[TMP1:%.*]] = sub i6 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[DIFF:%.*]] = shl i6 [[TMP1]], [[Z:%.*]]
; CHECK-NEXT: ret i6 [[DIFF]]
;
%xs = shl nsw i6 %x, %z
@ -242,9 +231,8 @@ define i6 @sub_shl_same_amount_partial_nsw1(i6 %x, i6 %y, i6 %z) {
define i6 @sub_shl_same_amount_partial_nsw2(i6 %x, i6 %y, i6 %z) {
; CHECK-LABEL: @sub_shl_same_amount_partial_nsw2(
; CHECK-NEXT: [[XS:%.*]] = shl i6 [[X:%.*]], [[Z:%.*]]
; CHECK-NEXT: [[YS:%.*]] = shl nsw i6 [[Y:%.*]], [[Z]]
; CHECK-NEXT: [[DIFF:%.*]] = sub nsw i6 [[XS]], [[YS]]
; CHECK-NEXT: [[TMP1:%.*]] = sub i6 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[DIFF:%.*]] = shl i6 [[TMP1]], [[Z:%.*]]
; CHECK-NEXT: ret i6 [[DIFF]]
;
%xs = shl i6 %x, %z
@ -255,9 +243,8 @@ define i6 @sub_shl_same_amount_partial_nsw2(i6 %x, i6 %y, i6 %z) {
define i6 @sub_shl_same_amount_partial_nuw1(i6 %x, i6 %y, i6 %z) {
; CHECK-LABEL: @sub_shl_same_amount_partial_nuw1(
; CHECK-NEXT: [[XS:%.*]] = shl nuw i6 [[X:%.*]], [[Z:%.*]]
; CHECK-NEXT: [[YS:%.*]] = shl nuw i6 [[Y:%.*]], [[Z]]
; CHECK-NEXT: [[DIFF:%.*]] = sub i6 [[XS]], [[YS]]
; CHECK-NEXT: [[TMP1:%.*]] = sub i6 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[DIFF:%.*]] = shl i6 [[TMP1]], [[Z:%.*]]
; CHECK-NEXT: ret i6 [[DIFF]]
;
%xs = shl nuw i6 %x, %z
@ -268,9 +255,8 @@ define i6 @sub_shl_same_amount_partial_nuw1(i6 %x, i6 %y, i6 %z) {
define i6 @sub_shl_same_amount_partial_nuw2(i6 %x, i6 %y, i6 %z) {
; CHECK-LABEL: @sub_shl_same_amount_partial_nuw2(
; CHECK-NEXT: [[XS:%.*]] = shl nuw i6 [[X:%.*]], [[Z:%.*]]
; CHECK-NEXT: [[YS:%.*]] = shl i6 [[Y:%.*]], [[Z]]
; CHECK-NEXT: [[DIFF:%.*]] = sub nuw i6 [[XS]], [[YS]]
; CHECK-NEXT: [[TMP1:%.*]] = sub i6 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[DIFF:%.*]] = shl i6 [[TMP1]], [[Z:%.*]]
; CHECK-NEXT: ret i6 [[DIFF]]
;
%xs = shl nuw i6 %x, %z