Insert denominator zero checks for NaCl

test/NaCl/ARM/divrem-guards-complex.ll

Index: test/NaCl/ARM/divrem-guards-complex.ll
diff --git a/test/NaCl/ARM/divrem-guards-complex.ll b/test/NaCl/ARM/divrem-guards-complex.ll
new file mode 100644
index 0000000000000000000000000000000000000000..ba66ab4b319d794de75371900d0b54e6a098abb1
--- /dev/null
+++ b/test/NaCl/ARM/divrem-guards-complex.ll
@@ -0,0 +1,85 @@
+; RUN: opt < %s -insert-divide-check -S | FileCheck -check-prefix=OPT %s
+
+declare void @foo()
+
+; Check for multiple divs that occur one block.
+define i32 @twodivs_one_block(i32 %x, i32 %y) #0 {
+entry:
+  call void @foo()
+  br label %divblock
+divblock:
+  %div1 = sdiv i32 %x, %y
+  %div2 = sdiv i32 %x, %y
+; OPT: %0 = icmp eq i32 %y, 0
+; OPT-NEXT: br i1 %0, label %divrem.by.zero, label %guarded.divrem
+; OPT: guarded.divrem:
+; OPT-NEXT: sdiv
+; OPT: %1 = icmp eq i32 %y, 0
+; OPT-NEXT: br i1 %1, label %divrem.by.zero1, label %guarded.divrem2
+; OPT: guarded.divrem2:
+; OPT-NEXT: sdiv
+; OPT-NEXT: add
+; OPT: divrem.by.zero:
+; OPT-NEXT: call void @llvm.trap()
+; OPT-NEXT: unreachable
+; OPT: divrem.by.zero1:
+; OPT-NEXT: call void @llvm.trap()
+; OPT-NEXT: unreachable
+  %sum = add i32 %div1, %div2
+  ret i32 %sum
+}
+
+define i32 @twodivs_three_blocks(i32 %x, i32 %y) #0 {
+entry:
+  call void @foo()
+  br label %divblock
+divblock:
+  %div1 = sdiv i32 %x, %y
+; OPT: %0 = icmp eq i32 %y, 0
+; OPT-NEXT: br i1 %0, label %divrem.by.zero, label %guarded.divrem
+; OPT: guarded.divrem:
+; OPT-NEXT: sdiv
+; OPT-NEXT: br label %exitblock
+  br label %exitblock
+exitblock:
+  call void @foo()
+  %div2 = sdiv i32 %x, %y
+; OPT: %1 = icmp eq i32 %y, 0
+; OPT-NEXT: br i1 %1, label %divrem.by.zero1, label %guarded.divrem2
+; OPT: guarded.divrem2:
+; OPT-NEXT: sdiv
+; OPT-NEXT: add
+; OPT: divrem.by.zero:
+; OPT-NEXT: call void @llvm.trap()
+; OPT-NEXT: unreachable
+; OPT: divrem.by.zero1:
+; OPT-NEXT: call void @llvm.trap()
+; OPT-NEXT: unreachable
+  %sum = add i32 %div1, %div2
+  ret i32 %sum
+}
+
+; Check for divs that occur in blocks with multiple predecessors.
+define i32 @onediv_two_predecessors(i32 %x, i32 %y) #0 {
+entry:
+  call void @foo()
+  br label %divblock
+divblock:
+  %x1 = phi i32 [%x, %entry], [%x2, %divblock]
+  %div1 = sdiv i32 %x, %y
+; OPT: %0 = icmp eq i32 %y, 0
+; OPT-NEXT: br i1 %0, label %divrem.by.zero, label %guarded.divrem
+; OPT: guarded.divrem:
+; OPT-NEXT: sdiv
+; OPT-NEXT: sub
+; OPT: divrem.by.zero:
+; OPT-NEXT: call void @llvm.trap()
+; OPT-NEXT: unreachable
+  %x2 = sub i32 %x1, 1
+  %p = icmp ne i32 %x2, 0
+  br i1 %p, label %divblock, label %exitblock
+exitblock:
+  call void @foo()
+  ret i32 %div1
+}
+