[GlobalOpt] add tests for constant expressions that can trap; NFC

https://llvm.org/PR47578

Author: rotateright

llvm/test/Transforms/GlobalOpt/constant-can-trap.ll

@@ -0,0 +1,83 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -passes=globalopt < %s -S | FileCheck %s
+
+@i = internal unnamed_addr global i32 1, align 4
+@r = internal global i64 0, align 8
+
+declare dso_local void @use(i32)
+
+define i32 @cantrap_constant() {
+; CHECK-LABEL: @cantrap_constant(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[DOTB:%.*]] = load i1, i1* @i, align 1
+; CHECK-NEXT:    [[TMP0:%.*]] = select i1 [[DOTB]], i32 trunc (i64 urem (i64 7, i64 zext (i1 icmp eq (i64* inttoptr (i64 1 to i64*), i64* @r) to i64)) to i32), i32 1
+; CHECK-NEXT:    [[TOBOOL:%.*]] = icmp eq i32 [[TMP0]], 0
+; CHECK-NEXT:    [[NOT_TOBOOL:%.*]] = xor i1 [[TOBOOL]], true
+; CHECK-NEXT:    [[SPEC_SELECT:%.*]] = zext i1 [[NOT_TOBOOL]] to i32
+; CHECK-NEXT:    tail call void @use(i32 [[SPEC_SELECT]])
+; CHECK-NEXT:    br i1 [[TOBOOL]], label [[IF_THEN:%.*]], label [[EXIT:%.*]]
+; CHECK:       if.then:
+; CHECK-NEXT:    store i1 true, i1* @i, align 1
+; CHECK-NEXT:    br label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret i32 0
+;
+entry:
+  %0 = load i32, i32* @i, align 4
+  %tobool = icmp eq i32 %0, 0
+  %not.tobool = xor i1 %tobool, true
+  %spec.select = zext i1 %not.tobool to i32
+  tail call void @use(i32 %spec.select)
+  br i1 %tobool, label %if.then, label %exit
+
+if.then:
+  store i32 trunc (i64 urem (i64 7, i64 zext (i1 icmp eq (i64* inttoptr (i64 1 to i64*), i64* @r) to i64)) to i32), i32* @i, align 4
+  br label %exit
+
+exit:
+  ret i32 0
+}
+
+@b1 = internal global i64* null, align 8
+@d1 = internal unnamed_addr global i32 0, align 2
+
+define void @maytrap() {
+; CHECK-LABEL: @maytrap(
+; CHECK-NEXT:    store i1 true, i1* @d1, align 1
+; CHECK-NEXT:    ret void
+;
+  store i32 srem (i32 7, i32 zext (i1 icmp eq (i64** inttoptr (i64 16 to i64**), i64** @b1) to i32)), i32* @d1, align 2
+  ret void
+}
+
+define i32 @main1() {
+; CHECK-LABEL: @main1(
+; CHECK-NEXT:    [[T0_B:%.*]] = load i1, i1* @d1, align 1
+; CHECK-NEXT:    [[T0:%.*]] = select i1 [[T0_B]], i32 srem (i32 7, i32 zext (i1 icmp eq (i64** inttoptr (i64 16 to i64**), i64** @b1) to i32)), i32 0
+; CHECK-NEXT:    ret i32 [[T0]]
+;
+  %t0 = load i32, i32* @d1, align 2
+  ret i32 %t0
+}
+
+@b2 = internal global i64* null, align 8
+@d2 = internal unnamed_addr global i32 0, align 2
+
+define void @maynottrap() {
+; CHECK-LABEL: @maynottrap(
+; CHECK-NEXT:    store i1 true, i1* @d2, align 1
+; CHECK-NEXT:    ret void
+;
+  store i32 mul (i32 7, i32 zext (i1 icmp eq (i64** inttoptr (i64 16 to i64**), i64** @b2) to i32)), i32* @d2, align 2
+  ret void
+}
+
+define i32 @main2() {
+; CHECK-LABEL: @main2(
+; CHECK-NEXT:    [[T0_B:%.*]] = load i1, i1* @d2, align 1
+; CHECK-NEXT:    [[T0:%.*]] = select i1 [[T0_B]], i32 mul (i32 zext (i1 icmp eq (i64** inttoptr (i64 16 to i64**), i64** @b2) to i32), i32 7), i32 0
+; CHECK-NEXT:    ret i32 [[T0]]
+;
+  %t0 = load i32, i32* @d2, align 2
+  ret i32 %t0
+}