[PhaseOrdering] Add test for loop over span with hardened libc++.

Add a slightly reduced test case for a loop iterating over a std::span
with libc++ hardening.

See https://godbolt.org/z/cKerYq9fY.

diff --git a/llvm/test/Transforms/PhaseOrdering/iterator-with-runtime-check.ll b/llvm/test/Transforms/PhaseOrdering/iterator-with-runtime-check.ll
new file mode 100644 (file)
index 0000000..ebe507d
--- /dev/null
+++ b/llvm/test/Transforms/PhaseOrdering/iterator-with-runtime-check.ll
@@ -0,0 +1,125 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 2
+; RUN: opt -passes='default<O2>' -S %s | FileCheck %s
+
+; Slightly reduced test case for a loop iterating over a std::span with libc++ hardening.
+; TODO: The runtime check in the loop should be removed.
+;
+; #include <span>
+; #include <iostream>
+;
+; void use(unsigned&);
+;
+; void fill_with_foreach(std::span<unsigned> elems) {
+;  for (unsigned& x : elems)
+;    use(x);
+; }
+
+%"class.std::__1::span" = type { ptr, i64 }
+%"struct.std::__1::__bounded_iter" = type { ptr, ptr, ptr }
+
+define void @test_fill_with_foreach([2 x i64] %elems.coerce) {
+; CHECK-LABEL: define void @test_fill_with_foreach
+; CHECK-SAME: ([2 x i64] [[ELEMS_COERCE:%.*]]) local_unnamed_addr {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[ELEMS_COERCE_FCA_0_EXTRACT:%.*]] = extractvalue [2 x i64] [[ELEMS_COERCE]], 0
+; CHECK-NEXT:    [[TMP0:%.*]] = inttoptr i64 [[ELEMS_COERCE_FCA_0_EXTRACT]] to ptr
+; CHECK-NEXT:    [[ELEMS_COERCE_FCA_1_EXTRACT:%.*]] = extractvalue [2 x i64] [[ELEMS_COERCE]], 1
+; CHECK-NEXT:    [[ADD_PTR_I:%.*]] = getelementptr i32, ptr [[TMP0]], i64 [[ELEMS_COERCE_FCA_1_EXTRACT]]
+; CHECK-NEXT:    [[CMP_NOT_I_I_I_I:%.*]] = icmp slt i64 [[ELEMS_COERCE_FCA_1_EXTRACT]], 0
+; CHECK-NEXT:    br i1 [[CMP_NOT_I_I_I_I]], label [[ERROR:%.*]], label [[FOR_COND_PREHEADER:%.*]]
+; CHECK:       for.cond.preheader:
+; CHECK-NEXT:    [[ADD_PTR_I_IDX_MASK:%.*]] = and i64 [[ELEMS_COERCE_FCA_1_EXTRACT]], 4611686018427387903
+; CHECK-NEXT:    [[CMP_I_NOT2:%.*]] = icmp eq i64 [[ADD_PTR_I_IDX_MASK]], 0
+; CHECK-NEXT:    br i1 [[CMP_I_NOT2]], label [[COMMON_RET:%.*]], label [[FOR_BODY:%.*]]
+; CHECK:       common.ret:
+; CHECK-NEXT:    ret void
+; CHECK:       error:
+; CHECK-NEXT:    tail call void @error()
+; CHECK-NEXT:    br label [[COMMON_RET]]
+; CHECK:       for.body:
+; CHECK-NEXT:    [[__BEGIN1_SROA_0_03:%.*]] = phi ptr [ [[INCDEC_PTR_I:%.*]], [[FOR_LATCH:%.*]] ], [ [[TMP0]], [[FOR_COND_PREHEADER]] ]
+; CHECK-NEXT:    [[CMP2_I_I:%.*]] = icmp ult ptr [[__BEGIN1_SROA_0_03]], [[ADD_PTR_I]]
+; CHECK-NEXT:    br i1 [[CMP2_I_I]], label [[FOR_LATCH]], label [[ERROR]]
+; CHECK:       for.latch:
+; CHECK-NEXT:    tail call void @use(ptr noundef nonnull align 4 dereferenceable(4) [[__BEGIN1_SROA_0_03]])
+; CHECK-NEXT:    [[INCDEC_PTR_I]] = getelementptr inbounds i32, ptr [[__BEGIN1_SROA_0_03]], i64 1
+; CHECK-NEXT:    [[CMP_I_NOT:%.*]] = icmp eq ptr [[INCDEC_PTR_I]], [[ADD_PTR_I]]
+; CHECK-NEXT:    br i1 [[CMP_I_NOT]], label [[COMMON_RET]], label [[FOR_BODY]]
+;
+entry:
+  %elems = alloca %"class.std::__1::span", align 8
+  %__begin1 = alloca %"struct.std::__1::__bounded_iter", align 8
+  %__end1 = alloca %"struct.std::__1::__bounded_iter", align 8
+  %elems.coerce.fca.0.extract = extractvalue [2 x i64] %elems.coerce, 0
+  store i64 %elems.coerce.fca.0.extract, ptr %elems, align 8
+  %elems.coerce.fca.1.extract = extractvalue [2 x i64] %elems.coerce, 1
+  %elems.coerce.fca.1.gep = getelementptr inbounds [2 x i64], ptr %elems, i64 0, i64 1
+  store i64 %elems.coerce.fca.1.extract, ptr %elems.coerce.fca.1.gep, align 8
+  call void @llvm.lifetime.start.p0(i64 24, ptr nonnull %__begin1) #6
+  %0 = load ptr, ptr %elems, align 8
+  %__size_.i.i = getelementptr inbounds %"class.std::__1::span", ptr %elems, i64 0, i32 1
+  %1 = load i64, ptr %__size_.i.i, align 8
+  %add.ptr.i = getelementptr inbounds i32, ptr %0, i64 %1
+  store ptr %0, ptr %__begin1, align 8
+  %__begin_.i.i.i.i = getelementptr inbounds %"struct.std::__1::__bounded_iter", ptr %__begin1, i64 0, i32 1
+  store ptr %0, ptr %__begin_.i.i.i.i, align 8
+  %__end_.i.i.i.i = getelementptr inbounds %"struct.std::__1::__bounded_iter", ptr %__begin1, i64 0, i32 2
+  store ptr %add.ptr.i, ptr %__end_.i.i.i.i, align 8
+  %cmp.not.i.i.i.i = icmp slt i64 %1, 0
+  br i1 %cmp.not.i.i.i.i, label %error, label %check.2
+
+check.2:
+  call void @llvm.lifetime.start.p0(i64 24, ptr nonnull %__end1) #6
+  %l4 = load ptr, ptr %elems, align 8
+  %__size_.i.i4 = getelementptr inbounds %"class.std::__1::span", ptr %elems, i64 0, i32 1
+  %l5 = load i64, ptr %__size_.i.i4, align 8
+  %add.ptr.i5 = getelementptr inbounds i32, ptr %l4, i64 %l5
+  store ptr %add.ptr.i5, ptr %__end1, align 8
+  %__begin_.i.i.i.i6 = getelementptr inbounds %"struct.std::__1::__bounded_iter", ptr %__end1, i64 0, i32 1
+  store ptr %l4, ptr %__begin_.i.i.i.i6, align 8
+  %__end_.i.i.i.i7 = getelementptr inbounds %"struct.std::__1::__bounded_iter", ptr %__end1, i64 0, i32 2
+  store ptr %add.ptr.i5, ptr %__end_.i.i.i.i7, align 8
+  %cmp.not.i.i.i.i8 = icmp slt i64 %l5, 0
+  br i1 %cmp.not.i.i.i.i8, label %error, label %for.cond
+
+error:
+  call void @error()
+  ret void
+
+for.cond:
+  %l8 = load ptr, ptr %__begin1, align 8
+  %l9 = load ptr, ptr %__end1, align 8
+  %cmp.i = icmp ne ptr %l8, %l9
+  br i1 %cmp.i, label %for.body, label %for.cond.cleanup
+
+for.cond.cleanup:                                 ; preds = %for.cond
+  call void @llvm.lifetime.end.p0(i64 24, ptr nonnull %__end1)
+  call void @llvm.lifetime.end.p0(i64 24, ptr nonnull %__begin1)
+  ret void
+
+for.body:                                         ; preds = %for.cond
+  %l10 = load ptr, ptr %__begin1, align 8
+  %__begin_.i.i = getelementptr inbounds %"struct.std::__1::__bounded_iter", ptr %__begin1, i64 0, i32 1
+  %l11 = load ptr, ptr %__begin_.i.i, align 8
+  %cmp.not.i.i = icmp uge ptr %l10, %l11
+  %__end_.i.i = getelementptr inbounds %"struct.std::__1::__bounded_iter", ptr %__begin1, i64 0, i32 2
+  %l12 = load ptr, ptr %__end_.i.i, align 8
+  %cmp2.i.i = icmp ult ptr %l10, %l12
+  %sel = select i1 %cmp.not.i.i, i1 %cmp2.i.i, i1 false
+  br i1 %sel, label %for.latch, label %error
+
+for.latch:
+  call void @use(ptr noundef nonnull align 4 dereferenceable(4) %l10)
+  %l = load ptr, ptr %__begin1, align 8
+  %incdec.ptr.i = getelementptr inbounds i32, ptr %l, i64 1
+  store ptr %incdec.ptr.i, ptr %__begin1, align 8
+  br label %for.cond
+}
+
+declare void @error()
+
+declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture)
+
+declare void @use(ptr noundef nonnull align 4 dereferenceable(4))
+
+declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture)