[PATCH] D109283: [InstCombine] ror/rol(X, RotAmt) == C --> X == rol/ror(C, RotAmt) (PR51567)
Dávid Bolvanský via Phabricator via llvm-commits
llvm-commits at lists.llvm.org
Tue Sep 7 09:05:12 PDT 2021
This revision was automatically updated to reflect the committed changes.
Closed by commit rG3b5f318f5d2d: [InstCombine] ror/rol(X, RotAmt) == C --> X == rol/ror(C, RotAmt) (PR51567) (authored by xbolva00).
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D109283/new/
https://reviews.llvm.org/D109283
Files:
llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
llvm/test/Transforms/InstCombine/icmp-rotate.ll
Index: llvm/test/Transforms/InstCombine/icmp-rotate.ll
===================================================================
--- llvm/test/Transforms/InstCombine/icmp-rotate.ll
+++ llvm/test/Transforms/InstCombine/icmp-rotate.ll
@@ -108,8 +108,7 @@
define i1 @rol_eq_cst(i8 %x) {
; CHECK-LABEL: @rol_eq_cst(
-; CHECK-NEXT: [[F:%.*]] = tail call i8 @llvm.fshl.i8(i8 [[X:%.*]], i8 [[X]], i8 3)
-; CHECK-NEXT: [[R:%.*]] = icmp eq i8 [[F]], 2
+; CHECK-NEXT: [[R:%.*]] = icmp eq i8 [[X:%.*]], 64
; CHECK-NEXT: ret i1 [[R]]
;
%f = tail call i8 @llvm.fshl.i8(i8 %x, i8 %x, i8 3)
@@ -119,8 +118,7 @@
define i1 @rol_ne_cst(i8 %x) {
; CHECK-LABEL: @rol_ne_cst(
-; CHECK-NEXT: [[F:%.*]] = tail call i8 @llvm.fshl.i8(i8 [[X:%.*]], i8 [[X]], i8 3)
-; CHECK-NEXT: [[R:%.*]] = icmp ne i8 [[F]], 2
+; CHECK-NEXT: [[R:%.*]] = icmp ne i8 [[X:%.*]], 64
; CHECK-NEXT: ret i1 [[R]]
;
%f = tail call i8 @llvm.fshl.i8(i8 %x, i8 %x, i8 3)
@@ -132,7 +130,7 @@
; CHECK-LABEL: @rol_eq_cst_use(
; CHECK-NEXT: [[F:%.*]] = tail call i8 @llvm.fshl.i8(i8 [[X:%.*]], i8 [[X]], i8 3)
; CHECK-NEXT: call void @use(i8 [[F]])
-; CHECK-NEXT: [[R:%.*]] = icmp eq i8 [[F]], 2
+; CHECK-NEXT: [[R:%.*]] = icmp eq i8 [[X]], 64
; CHECK-NEXT: ret i1 [[R]]
;
%f = tail call i8 @llvm.fshl.i8(i8 %x, i8 %x, i8 3)
@@ -143,8 +141,7 @@
define i1 @ror_eq_cst(i8 %x) {
; CHECK-LABEL: @ror_eq_cst(
-; CHECK-NEXT: [[F:%.*]] = call i8 @llvm.fshl.i8(i8 [[X:%.*]], i8 [[X]], i8 6)
-; CHECK-NEXT: [[R:%.*]] = icmp eq i8 [[F]], 3
+; CHECK-NEXT: [[R:%.*]] = icmp eq i8 [[X:%.*]], 12
; CHECK-NEXT: ret i1 [[R]]
;
%f = tail call i8 @llvm.fshr.i8(i8 %x, i8 %x, i8 2)
@@ -154,8 +151,7 @@
define i1 @ror_ne_cst(i8 %x) {
; CHECK-LABEL: @ror_ne_cst(
-; CHECK-NEXT: [[F:%.*]] = call i8 @llvm.fshl.i8(i8 [[X:%.*]], i8 [[X]], i8 6)
-; CHECK-NEXT: [[R:%.*]] = icmp ne i8 [[F]], 3
+; CHECK-NEXT: [[R:%.*]] = icmp ne i8 [[X:%.*]], 12
; CHECK-NEXT: ret i1 [[R]]
;
%f = tail call i8 @llvm.fshr.i8(i8 %x, i8 %x, i8 2)
@@ -165,8 +161,7 @@
define <2 x i1> @rol_eq_cst_vec(<2 x i5> %x) {
; CHECK-LABEL: @rol_eq_cst_vec(
-; CHECK-NEXT: [[F:%.*]] = tail call <2 x i5> @llvm.fshl.v2i5(<2 x i5> [[X:%.*]], <2 x i5> [[X]], <2 x i5> <i5 3, i5 3>)
-; CHECK-NEXT: [[R:%.*]] = icmp eq <2 x i5> [[F]], <i5 2, i5 2>
+; CHECK-NEXT: [[R:%.*]] = icmp eq <2 x i5> [[X:%.*]], <i5 8, i5 8>
; CHECK-NEXT: ret <2 x i1> [[R]]
;
%f = tail call <2 x i5> @llvm.fshl.v2i5(<2 x i5> %x, <2 x i5> %x, <2 x i5> <i5 3, i5 3>)
Index: llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
===================================================================
--- llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -3228,12 +3228,22 @@
case Intrinsic::fshl:
case Intrinsic::fshr:
- // (rot X, ?) == 0/-1 --> X == 0/-1
- // TODO: This transform is safe to re-use undef elts in a vector, but
- // the constant value passed in by the caller doesn't allow that.
- if (C.isNullValue() || C.isAllOnesValue())
- if (II->getArgOperand(0) == II->getArgOperand(1))
+ if (II->getArgOperand(0) == II->getArgOperand(1)) {
+ // (rot X, ?) == 0/-1 --> X == 0/-1
+ // TODO: This transform is safe to re-use undef elts in a vector, but
+ // the constant value passed in by the caller doesn't allow that.
+ if (C.isNullValue() || C.isAllOnesValue())
return new ICmpInst(Pred, II->getArgOperand(0), Cmp.getOperand(1));
+
+ const APInt *RotAmtC;
+ // ror(X, RotAmtC) == C --> X == rol(C, RotAmtC)
+ // rol(X, RotAmtC) == C --> X == ror(C, RotAmtC)
+ if (match(II->getArgOperand(2), m_APInt(RotAmtC)))
+ return new ICmpInst(Pred, II->getArgOperand(0),
+ II->getIntrinsicID() == Intrinsic::fshl
+ ? ConstantInt::get(Ty, C.rotr(*RotAmtC))
+ : ConstantInt::get(Ty, C.rotl(*RotAmtC)));
+ }
break;
case Intrinsic::uadd_sat: {
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