IndVarSimplify: add samesign test from a regression

llvm/test/Analysis/ScalarEvolution/exit-count-samesign.ll

@@ -0,0 +1,42 @@
+; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py UTC_ARGS: --version 5
+; RUN: opt -disable-output "-passes=print<scalar-evolution>" \
+; RUN:  -scalar-evolution-classify-expressions=0 < %s 2>&1 | FileCheck %s
+
+define i32 @exit_count_samesign(i32 %iter.count, ptr %ptr) {
+; CHECK-LABEL: 'exit_count_samesign'
+; CHECK-NEXT:  Determining loop execution counts for: @exit_count_samesign
+; CHECK-NEXT:  Loop %inner.loop: backedge-taken count is (-1 + (1 smax {(-1 + %iter.count)<nsw>,+,-1}<nsw><%outer.loop>))<nsw>
+; CHECK-NEXT:  Loop %inner.loop: constant max backedge-taken count is i32 2147483646
+; CHECK-NEXT:  Loop %inner.loop: symbolic max backedge-taken count is (-1 + (1 smax {(-1 + %iter.count)<nsw>,+,-1}<nsw><%outer.loop>))<nsw>
+; CHECK-NEXT:  Loop %inner.loop: Trip multiple is 1
+; CHECK-NEXT:  Loop %outer.loop: <multiple exits> Unpredictable backedge-taken count.
+; CHECK-NEXT:  Loop %outer.loop: Unpredictable constant max backedge-taken count.
+; CHECK-NEXT:  Loop %outer.loop: Unpredictable symbolic max backedge-taken count.
+;
+entry:
+  br label %outer.loop
+
+ph:
+  br label %outer.loop
+
+outer.loop:
+  %iv.outer = phi i32 [ %iv.outer.1, %ph ], [ %iter.count, %entry ]
+  %iv.outer.1 = add nsw i32 %iv.outer, -1
+  %ext.outer = zext nneg i32 %iv.outer.1 to i64
+  %gep.outer = getelementptr double, ptr %ptr, i64 %ext.outer
+  store double poison, ptr %gep.outer
+  %exit.cond.outer = icmp samesign ugt i32 %iv.outer, 1
+  br i1 %exit.cond.outer, label %inner.loop, label %ph
+
+inner.loop:
+  %iv.inner = phi i32 [ %iv.next, %inner.loop ], [ 0, %outer.loop ]
+  %ext.inner = zext nneg i32 %iv.inner to i64
+  %gep.inner = getelementptr double, ptr %ptr, i64 %ext.inner
+  store double poison, ptr %gep.inner
+  %iv.next = add nuw nsw i32 %iv.inner, 1
+  %exit.cond.inner = icmp slt i32 %iv.next, %iv.outer.1
+  br i1 %exit.cond.inner, label %inner.loop, label %ph
+
+exit:
+  ret i32 0
+}

llvm/test/Transforms/IndVarSimplify/iv-zext-samesign-datalayout.ll

@@ -0,0 +1,62 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt < %s -passes=indvars -S | FileCheck %s
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
+
+define i32 @iv_zext_samesign(i32 %iter.count, ptr %ptr) {
+; CHECK-LABEL: define i32 @iv_zext_samesign(
+; CHECK-SAME: i32 [[ITER_COUNT:%.*]], ptr [[PTR:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    [[TMP0:%.*]] = sext i32 [[ITER_COUNT]] to i64
+; CHECK-NEXT:    br label %[[OUTER_LOOP:.*]]
+; CHECK:       [[PH_LOOPEXIT:.*]]:
+; CHECK-NEXT:    br label %[[PH:.*]]
+; CHECK:       [[PH]]:
+; CHECK-NEXT:    br label %[[OUTER_LOOP]]
+; CHECK:       [[OUTER_LOOP]]:
+; CHECK-NEXT:    [[INDVARS_IV1:%.*]] = phi i64 [ [[INDVARS_IV_NEXT2:%.*]], %[[PH]] ], [ [[TMP0]], %[[ENTRY]] ]
+; CHECK-NEXT:    [[INDVARS_IV_NEXT2]] = add nsw i64 [[INDVARS_IV1]], -1
+; CHECK-NEXT:    [[GEP_OUTER:%.*]] = getelementptr double, ptr [[PTR]], i64 [[INDVARS_IV_NEXT2]]
+; CHECK-NEXT:    store double poison, ptr [[GEP_OUTER]], align 8
+; CHECK-NEXT:    [[TMP1:%.*]] = trunc nsw i64 [[INDVARS_IV1]] to i32
+; CHECK-NEXT:    [[EXIT_COND_OUTER:%.*]] = icmp samesign ugt i32 [[TMP1]], 1
+; CHECK-NEXT:    br i1 [[EXIT_COND_OUTER]], label %[[INNER_LOOP_PREHEADER:.*]], label %[[PH]]
+; CHECK:       [[INNER_LOOP_PREHEADER]]:
+; CHECK-NEXT:    br label %[[INNER_LOOP:.*]]
+; CHECK:       [[INNER_LOOP]]:
+; CHECK-NEXT:    [[INDVARS_IV:%.*]] = phi i64 [ 0, %[[INNER_LOOP_PREHEADER]] ], [ [[INDVARS_IV_NEXT:%.*]], %[[INNER_LOOP]] ]
+; CHECK-NEXT:    [[GEP_INNER:%.*]] = getelementptr double, ptr [[PTR]], i64 [[INDVARS_IV]]
+; CHECK-NEXT:    store double poison, ptr [[GEP_INNER]], align 8
+; CHECK-NEXT:    [[INDVARS_IV_NEXT]] = add nuw nsw i64 [[INDVARS_IV]], 1
+; CHECK-NEXT:    [[EXIT_COND_INNER:%.*]] = icmp slt i64 [[INDVARS_IV_NEXT]], [[INDVARS_IV_NEXT2]]
+; CHECK-NEXT:    br i1 [[EXIT_COND_INNER]], label %[[INNER_LOOP]], label %[[PH_LOOPEXIT]]
+; CHECK:       [[EXIT:.*:]]
+; CHECK-NEXT:    ret i32 0
+;
+entry:
+  br label %outer.loop
+
+ph:
+  br label %outer.loop
+
+outer.loop:
+  %iv.outer = phi i32 [ %iv.outer.1, %ph ], [ %iter.count, %entry ]
+  %iv.outer.1 = add nsw i32 %iv.outer, -1
+  %ext.outer = zext nneg i32 %iv.outer.1 to i64
+  %gep.outer = getelementptr double, ptr %ptr, i64 %ext.outer
+  store double poison, ptr %gep.outer
+  %exit.cond.outer = icmp samesign ugt i32 %iv.outer, 1
+  br i1 %exit.cond.outer, label %inner.loop, label %ph
+
+inner.loop:
+  %iv.inner = phi i32 [ %iv.next, %inner.loop ], [ 0, %outer.loop ]
+  %ext.inner = zext nneg i32 %iv.inner to i64
+  %gep.inner = getelementptr double, ptr %ptr, i64 %ext.inner
+  store double poison, ptr %gep.inner
+  %iv.next = add nuw nsw i32 %iv.inner, 1
+  %exit.cond.inner = icmp slt i32 %iv.next, %iv.outer.1
+  br i1 %exit.cond.inner, label %inner.loop, label %ph
+
+exit:
+  ret i32 0
+}