!fixup add both

Author: fhahn

llvm/lib/Analysis/ScalarEvolution.cpp

@@ -15834,9 +15834,14 @@ void ScalarEvolution::LoopGuards::collectFromBlock(
             if (isa<SCEVCouldNotCompute>(LHS) || isa<SCEVCouldNotCompute>(RHS))
               break;
           }
-          From = SE.getMinusSCEV(RHS, LHS);
-          FromRewritten = From;
-          To = SE.getUMaxExpr(FromRewritten, SE.getOne(From->getType()));
+          auto AddSubRewrite = [&](const SCEV *A, const SCEV *B) {
+            const SCEV *Sub = SE.getMinusSCEV(A, B);
+            AddRewrite(Sub, Sub,
+                       SE.getUMaxExpr(Sub, SE.getOne(From->getType())));
+          };
+          AddSubRewrite(LHS, RHS);
+          AddSubRewrite(RHS, LHS);
+          continue;
         }
         break;
       default:

llvm/test/Analysis/ScalarEvolution/ptrtoint.ll

@@ -459,7 +459,7 @@ define void @pr46786_c26_char_cmp_ops_swapped(ptr %arg, ptr %arg1, ptr %arg2) {
 ; X64-NEXT:    %i9 = ptrtoint ptr %i7 to i64
 ; X64-NEXT:    --> {(ptrtoint ptr %arg to i64),+,1}<nuw><%bb6> U: full-set S: full-set Exits: (-1 + (ptrtoint ptr %arg1 to i64)) LoopDispositions: { %bb6: Computable }
 ; X64-NEXT:    %i10 = sub i64 %i9, %i4
-; X64-NEXT:    --> {0,+,1}<nuw><%bb6> U: full-set S: full-set Exits: (-1 + (-1 * (ptrtoint ptr %arg to i64)) + (ptrtoint ptr %arg1 to i64)) LoopDispositions: { %bb6: Computable }
+; X64-NEXT:    --> {0,+,1}<nuw><%bb6> U: [0,-1) S: [0,-1) Exits: (-1 + (-1 * (ptrtoint ptr %arg to i64)) + (ptrtoint ptr %arg1 to i64)) LoopDispositions: { %bb6: Computable }
 ; X64-NEXT:    %i11 = getelementptr inbounds i8, ptr %arg2, i64 %i10
 ; X64-NEXT:    --> {%arg2,+,1}<nw><%bb6> U: full-set S: full-set Exits: (-1 + (-1 * (ptrtoint ptr %arg to i64)) + (ptrtoint ptr %arg1 to i64) + %arg2) LoopDispositions: { %bb6: Computable }
 ; X64-NEXT:    %i12 = load i8, ptr %i11, align 1
@@ -470,7 +470,7 @@ define void @pr46786_c26_char_cmp_ops_swapped(ptr %arg, ptr %arg1, ptr %arg2) {
 ; X64-NEXT:    --> {(1 + %arg),+,1}<nuw><%bb6> U: full-set S: full-set Exits: ((-1 * (ptrtoint ptr %arg to i64)) + (ptrtoint ptr %arg1 to i64) + %arg) LoopDispositions: { %bb6: Computable }
 ; X64-NEXT:  Determining loop execution counts for: @pr46786_c26_char_cmp_ops_swapped
 ; X64-NEXT:  Loop %bb6: backedge-taken count is (-1 + (-1 * (ptrtoint ptr %arg to i64)) + (ptrtoint ptr %arg1 to i64))
-; X64-NEXT:  Loop %bb6: constant max backedge-taken count is i64 -1
+; X64-NEXT:  Loop %bb6: constant max backedge-taken count is i64 -2
 ; X64-NEXT:  Loop %bb6: symbolic max backedge-taken count is (-1 + (-1 * (ptrtoint ptr %arg to i64)) + (ptrtoint ptr %arg1 to i64))
 ; X64-NEXT:  Loop %bb6: Trip multiple is 1
 ;
@@ -483,9 +483,9 @@ define void @pr46786_c26_char_cmp_ops_swapped(ptr %arg, ptr %arg1, ptr %arg2) {
 ; X32-NEXT:    %i8 = load i8, ptr %i7, align 1
 ; X32-NEXT:    --> %i8 U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %bb6: Variant }
 ; X32-NEXT:    %i9 = ptrtoint ptr %i7 to i64
-; X32-NEXT:    --> {(zext i32 (ptrtoint ptr %arg to i32) to i64),+,1}<nuw><%bb6> U: [0,8589934591) S: [0,8589934591) Exits: ((zext i32 (-1 + (-1 * (ptrtoint ptr %arg to i32)) + (ptrtoint ptr %arg1 to i32)) to i64) + (zext i32 (ptrtoint ptr %arg to i32) to i64)) LoopDispositions: { %bb6: Computable }
+; X32-NEXT:    --> {(zext i32 (ptrtoint ptr %arg to i32) to i64),+,1}<nuw><%bb6> U: [0,8589934590) S: [0,8589934590) Exits: ((zext i32 (-1 + (-1 * (ptrtoint ptr %arg to i32)) + (ptrtoint ptr %arg1 to i32)) to i64) + (zext i32 (ptrtoint ptr %arg to i32) to i64)) LoopDispositions: { %bb6: Computable }
 ; X32-NEXT:    %i10 = sub i64 %i9, %i4
-; X32-NEXT:    --> {0,+,1}<nuw><%bb6> U: [0,4294967296) S: [0,4294967296) Exits: (zext i32 (-1 + (-1 * (ptrtoint ptr %arg to i32)) + (ptrtoint ptr %arg1 to i32)) to i64) LoopDispositions: { %bb6: Computable }
+; X32-NEXT:    --> {0,+,1}<nuw><%bb6> U: [0,4294967295) S: [0,4294967295) Exits: (zext i32 (-1 + (-1 * (ptrtoint ptr %arg to i32)) + (ptrtoint ptr %arg1 to i32)) to i64) LoopDispositions: { %bb6: Computable }
 ; X32-NEXT:    %i11 = getelementptr inbounds i8, ptr %arg2, i64 %i10
 ; X32-NEXT:    --> {%arg2,+,1}<%bb6> U: full-set S: full-set Exits: (-1 + (-1 * (ptrtoint ptr %arg to i32)) + (ptrtoint ptr %arg1 to i32) + %arg2) LoopDispositions: { %bb6: Computable }
 ; X32-NEXT:    %i12 = load i8, ptr %i11, align 1
@@ -496,7 +496,7 @@ define void @pr46786_c26_char_cmp_ops_swapped(ptr %arg, ptr %arg1, ptr %arg2) {
 ; X32-NEXT:    --> {(1 + %arg),+,1}<nuw><%bb6> U: full-set S: full-set Exits: ((-1 * (ptrtoint ptr %arg to i32)) + (ptrtoint ptr %arg1 to i32) + %arg) LoopDispositions: { %bb6: Computable }
 ; X32-NEXT:  Determining loop execution counts for: @pr46786_c26_char_cmp_ops_swapped
 ; X32-NEXT:  Loop %bb6: backedge-taken count is (-1 + (-1 * (ptrtoint ptr %arg to i32)) + (ptrtoint ptr %arg1 to i32))
-; X32-NEXT:  Loop %bb6: constant max backedge-taken count is i32 -1
+; X32-NEXT:  Loop %bb6: constant max backedge-taken count is i32 -2
 ; X32-NEXT:  Loop %bb6: symbolic max backedge-taken count is (-1 + (-1 * (ptrtoint ptr %arg to i32)) + (ptrtoint ptr %arg1 to i32))
 ; X32-NEXT:  Loop %bb6: Trip multiple is 1
 ;