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

2 files changed, 56 insertions, 10 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: }
diff --git a/test/NaCl/Bitcode/ptrtoint-elide.ll b/test/NaCl/Bitcode/ptrtoint-elide.ll
index bfca601d3f..5c95a79789 100644
--- a/test/NaCl/Bitcode/ptrtoint-elide.ll
+++ b/test/NaCl/Bitcode/ptrtoint-elide.ll
@@ -1016,35 +1016,35 @@ start:
 ; TD2:      define void @PhiForwardRefs(i1) {
 ; TD2-NEXT:   br label %start
 ; TD2:      merge
-; TD2-NEXT:   %2 = phi i32 [ %6, %true ], [ %9, %false ]
-; TD2-NEXT:   %3 = phi i32 [ %5, %true ], [ %8, %false ]
+; TD2-NEXT:   %2 = phi i32 [ %11, %true ], [ %11, %false ]
+; TD2-NEXT:   %3 = phi i32 [ %5, %true ], [ %7, %false ]
 ; TD2-NEXT:   ret void
 ; TD2:      true:
-; TD2-NEXT:   %4 = bitcast i8* %10 to i32*
+; TD2-NEXT:   %4 = inttoptr i32 %9 to i32*
 ; TD2-NEXT:   %5 = load i32* %4
-; TD2-NEXT:   %6 = ptrtoint i8* %11 to i32
 ; TD2-NEXT:   br label %merge
 ; TD2:      false:
-; TD2-NEXT:   %7 = bitcast i8* %10 to i32*
-; TD2-NEXT:   %8 = load i32* %7
-; TD2-NEXT:   %9 = ptrtoint i8* %11 to i32
+; TD2-NEXT:   %6 = inttoptr i32 %9 to i32*
+; TD2-NEXT:   %7 = load i32* %6
 ; TD2-NEXT:   br label %merge
 ; TD2:      start:
+; TD2-NEXT:   %8 = alloca i8, i32 4, align 8
+; TD2-NEXT:   %9 = ptrtoint i8* %8 to i32
 ; TD2-NEXT:   %10 = alloca i8, i32 4, align 8
-; TD2-NEXT:   %11 = alloca i8, i32 4, align 8
+; TD2-NEXT:   %11 = ptrtoint i8* %10 to i32
 ; TD2-NEXT:   br i1 %0, label %true, label %false
 ; TD2-NEXT: }
 
 ; PF2:        <FUNCTION_BLOCK>
 ; PF2:          </CONSTANTS_BLOCK>
 ; PF2-NEXT:     <INST_BR op0=4/>
-; PF2-NEXT:     <FORWARDTYPEREF op0=28 op1=3/>
+; PF2-NEXT:     <FORWARDTYPEREF op0=28 op1=0/>
 ; PF2-NEXT:     <INST_PHI op0=0 op1=11 op2=2 op3=11 op4=3/>
 ; PF2-NEXT:     <FORWARDTYPEREF op0=25 op1=0/>
 ; PF2-NEXT:     <FORWARDTYPEREF op0=26 op1=0/>
 ; PF2-NEXT:     <INST_PHI op0=0 op1=3 op2=2 op3=5 op4=3/>
 ; PF2-NEXT:     <INST_RET/>
-; PF2-NEXT:     <FORWARDTYPEREF op0=27 op1=3/>
+; PF2-NEXT:     <FORWARDTYPEREF op0=27 op1=0/>
 ; PF2-NEXT:     <INST_LOAD op0=4294967294 op1=0 op2=0/>
 ; PF2-NEXT:     <INST_BR op0=1/>
 ; PF2-NEXT:     <INST_LOAD op0=4294967295 op1=0 op2=0/>