PNaCl bitcode: Change FORWARDTYPEREF to never use pointer types

Before, FORWARDTYPEREFs used i8* type rather than i32 if they
referenced an "alloca" instruction.

Clean this up so that FORWARDTYPEREFs use i32 instead in this case.

Note that this means that a forward-referenced "alloca" can be used
via an ptrtoint+inttoptr, rather than a bitcast, but that's no
problem.

This is a step towards removing TYPE_CODE_POINTER from the types
table, to simplify the PNaCl bitcode format.

Rename NormalizeParamType() to NormalizeScalarType() to reflect that
it's used in more cases; make it public.

BUG=https://code.google.com/p/nativeclient/issues/detail?id=3671
TEST=test/NaCl/Bitcode/*.ll

Review URL: https://codereview.chromium.org/23719016

1 files changed, 46 insertions, 0 deletions

diff --git a/test/NaCl/Bitcode/forward-ref-pointer-intrinsic.ll b/test/NaCl/Bitcode/forward-ref-pointer-intrinsic.ll
new file mode 100644
index 0000000000..b6f8124a6f
--- /dev/null
+++ b/test/NaCl/Bitcode/forward-ref-pointer-intrinsic.ll
@@ -0,0 +1,46 @@
+; Test forward reference of a pointer-typed intrinsic result.
+
+; RUN: llvm-as < %s | pnacl-freeze --pnacl-version=1 | pnacl-thaw \
+; RUN:              | llvm-dis - | FileCheck %s -check-prefix=TD1
+
+; RUN: llvm-as < %s | pnacl-freeze --pnacl-version=2 | pnacl-thaw \
+; RUN:              | llvm-dis - | FileCheck %s -check-prefix=TD2
+
+
+declare i8* @llvm.nacl.read.tp()
+
+define i32 @forward_ref() {
+  br label %block1
+
+block2:
+  %1 = load i8* %3
+  %2 = ptrtoint i8* %3 to i32
+  ret i32 %2
+
+block1:
+  %3 = call i8* @llvm.nacl.read.tp()
+  br label %block2
+}
+
+; TD1:      define i32 @forward_ref() {
+; TD1-NEXT:   br label %block1
+; TD1:      block2:
+; TD1-NEXT:   %1 = load i8* %3
+; TD1-NEXT:   %2 = ptrtoint i8* %3 to i32
+; TD1-NEXT:   ret i32 %2
+; TD1:      block1:
+; TD1-NEXT:   %3 = call i8* @llvm.nacl.read.tp()
+; TD1-NEXT:   br label %block2
+; TD1-NEXT: }
+
+; TD2:      define i32 @forward_ref() {
+; TD2-NEXT:   br label %block1
+; TD2:      block2:
+; TD2-NEXT:   %1 = inttoptr i32 %4 to i8*
+; TD2-NEXT:   %2 = load i8* %1
+; TD2-NEXT:   ret i32 %4
+; TD2:      block1:
+; TD2-NEXT:   %3 = call i8* @llvm.nacl.read.tp()
+; TD2-NEXT:   %4 = ptrtoint i8* %3 to i32
+; TD2-NEXT:   br label %block2
+; TD2-NEXT: }