Add call instructions to Subzero's bitcode reader.

tests_lit/reader_tests/call.ll

+; Test handling of call instructions.
+
+; RUN: llvm-as < %s | pnacl-freeze -allow-local-symbol-tables \
+; RUN:              | %llvm2ice -notranslate -verbose=inst -build-on-read \
+; RUN:                -allow-pnacl-reader-error-recovery \
+; RUN:                -allow-local-symbol-tables \
+; RUN:              | FileCheck %s
+
+define i32 @fib(i32 %n) {

[Jim Stichnoth, 2014/09/18 21:41:54]

Just so I don't have to pore through all these tests...  Are there any
differences between these and the ones with the same name in the lit tests? 
(other than the RUN and CHECK lines)

[Karl, 2014/09/18 22:01:50]

Almost. I removed duplicate calls to an intrinsic that was testing downstream
additional compilation issues (ones with suffices more_addressing, dead, align,
const_len, mergeable_load, const, ignored, multiple, with_arith, alloca, loop,
store).

[jvoung (off chromium), 2014/09/18 23:43:53]

Hmm I'm not sure you need to have calls to all the intrinsics, but okay.

Eventually we will switch the default reader over to this one, and then the
other tests will cover the same.

I think what would have been good to add is a test for a non-existent intrinsic,
or one with bad type signature.

[Karl, 2014/09/19 20:29:51]

I can't test a bad type signature, because llvm-as complains about this.
However, added file nacl-fake-intrinsic.ll that tests for a non-existent
intrinsic.

+entry:
+  %cmp = icmp slt i32 %n, 2
+  br i1 %cmp, label %return, label %if.end
+
+if.end:                                           ; preds = %entry
+  %sub = add i32 %n, -1
+  %call = tail call i32 @fib(i32 %sub)
+  %sub1 = add i32 %n, -2
+  %call2 = tail call i32 @fib(i32 %sub1)
+  %add = add i32 %call2, %call
+  ret i32 %add
+
+return:                                           ; preds = %entry
+  ret i32 %n
+}
+
+; CHECK:      define i32 @fib(i32 %n) {
+; CHECK-NEXT: entry:
+; CHECK-NEXT:   %cmp = icmp slt i32 %n, 2
+; CHECK-NEXT:   br i1 %cmp, label %return, label %if.end
+; CHECK-NEXT: if.end:
+; CHECK-NEXT:   %sub = add i32 %n, -1
+; CHECK-NEXT:   %call = call i32 @fib(i32 %sub)
+; CHECK-NEXT:   %sub1 = add i32 %n, -2
+; CHECK-NEXT:   %call2 = call i32 @fib(i32 %sub1)
+; CHECK-NEXT:   %add = add i32 %call2, %call
+; CHECK-NEXT:   ret i32 %add
+; CHECK-NEXT: return:
+; CHECK-NEXT:   ret i32 %n
+; CHECK-NEXT: }
+
+define i32 @fact(i32 %n) {
+entry:
+  %cmp = icmp slt i32 %n, 2
+  br i1 %cmp, label %return, label %if.end
+
+if.end:                                           ; preds = %entry
+  %sub = add i32 %n, -1
+  %call = tail call i32 @fact(i32 %sub)
+  %mul = mul i32 %call, %n
+  ret i32 %mul
+
+return:                                           ; preds = %entry
+  ret i32 %n
+}
+
+; CHECK-NEXT: define i32 @fact(i32 %n) {
+; CHECK-NEXT: entry:
+; CHECK-NEXT:   %cmp = icmp slt i32 %n, 2
+; CHECK-NEXT:   br i1 %cmp, label %return, label %if.end
+; CHECK-NEXT: if.end:
+; CHECK-NEXT:   %sub = add i32 %n, -1
+; CHECK-NEXT:   %call = call i32 @fact(i32 %sub)
+; CHECK-NEXT:   %mul = mul i32 %call, %n
+; CHECK-NEXT:   ret i32 %mul
+; CHECK-NEXT: return:
+; CHECK-NEXT:   ret i32 %n
+; CHECK-NEXT: }
+
+define i32 @redirect(i32 %n) {
+entry:
+  %call = tail call i32 @redirect_target(i32 %n)
+  ret i32 %call
+}
+
+; CHECK-NEXT: define i32 @redirect(i32 %n) {
+; CHECK-NEXT: entry:
+; CHECK-NEXT:   %call = call i32 @redirect_target(i32 %n)
+; CHECK-NEXT:   ret i32 %call
+; CHECK-NEXT: }
+
+declare i32 @redirect_target(i32)
+
+define void @call_void(i32 %n) {
+entry:
+  %cmp2 = icmp sgt i32 %n, 0
+  br i1 %cmp2, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry, %if.then
+  %n.tr3 = phi i32 [ %call.i, %if.then ], [ %n, %entry ]
+  %sub = add i32 %n.tr3, -1
+  %call.i = tail call i32 @redirect_target(i32 %sub)
+  %cmp = icmp sgt i32 %call.i, 0
+  br i1 %cmp, label %if.then, label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  ret void
+}
+
+; CHECK-NEXT: define void @call_void(i32 %n) {
+; CHECK-NEXT: entry:
+; CHECK-NEXT:   %cmp2 = icmp sgt i32 %n, 0
+; CHECK-NEXT:   br i1 %cmp2, label %if.then, label %if.end
+; CHECK-NEXT: if.then:
+; CHECK-NEXT:   %n.tr3 = phi i32 [ %call.i, %if.then ], [ %n, %entry ]
+; CHECK-NEXT:   %sub = add i32 %n.tr3, -1
+; CHECK-NEXT:   %call.i = call i32 @redirect_target(i32 %sub)
+; CHECK-NEXT:   %cmp = icmp sgt i32 %call.i, 0
+; CHECK-NEXT:   br i1 %cmp, label %if.then, label %if.end
+; CHECK-NEXT: if.end:
+; CHECK-NEXT:   ret void
+; CHECK-NEXT: }
+