Add alloca instruction to Subzero bitcode reader.

tests_lit/reader_tests/alloca.ll

+; Test if we can read alloca instructions.
+
+; RUN: llvm-as < %s | pnacl-freeze \
+; RUN:              | %llvm2ice -notranslate -verbose=inst -build-on-read \
+; RUN:                -allow-pnacl-reader-error-recovery \
+; RUN:              | FileCheck %s
+
+; Show examples where size is defined by a constant.
+
+define i32 @AllocaA0Size1() {
+  %array = alloca i8, i32 1
+  %addr = ptrtoint i8* %array to i32
+  ret i32 %addr
+
+; CHECK:      __0:

[jvoung (off chromium), 2014/09/08 23:31:23]

Hmm, most of the tests do "CHECK-LABEL: function_name", instead of CHECK: __0:,
so this seems a little unusual. Why not use the function_name instead for
consistency? Because of the CHECK-NEXT setup?

[Jim Stichnoth, 2014/09/08 23:54:40]

I think CHECK-LABEL is only appropriate for emitted code, but this is testing
just the bitcode dump.

Along those lines, it's better to put a named "entry:" label in the entry basic
block if you eventually want to use szdiff.py, but I suspect that labels aren't
yet supported.

[Karl, 2014/09/10 17:29:59]

Since we aren't handling valuesymtab blocks within functions yet, we can't give
them a good name.

+; CHECK-NEXT:   %__0 = alloca i8, i32 1, align 0
+; CHECK-NEXT:   ret i32 %__0
+}
+
+define i32 @AllocaA0Size2() {
+  %array = alloca i8, i32 2
+  %addr = ptrtoint i8* %array to i32
+  ret i32 %addr
+
+; CHECK:      __0:
+; CHECK-NEXT:   %__0 = alloca i8, i32 2, align 0
+; CHECK-NEXT:   ret i32 %__0
+}
+
+define i32 @AllocaA0Size3() {
+  %array = alloca i8, i32 3
+  %addr = ptrtoint i8* %array to i32
+  ret i32 %addr
+
+; CHECK:      __0:
+; CHECK-NEXT:   %__0 = alloca i8, i32 3, align 0
+; CHECK-NEXT:   ret i32 %__0
+}
+
+define i32 @AllocaA0Size4() {
+  %array = alloca i8, i32 4
+  %addr = ptrtoint i8* %array to i32
+  ret i32 %addr
+
+; CHECK:      __0:
+; CHECK-NEXT:   %__0 = alloca i8, i32 4, align 0
+; CHECK-NEXT:   ret i32 %__0
+}
+
+define i32 @AllocaA1Size4(i32 %n) {
+  %array = alloca i8, i32 4, align 1
+  %addr = ptrtoint i8* %array to i32
+  ret i32 %addr
+
+; CHECK:      __0:
+; CHECK-NEXT:   %__1 = alloca i8, i32 4, align 1
+; CHECK-NEXT:   ret i32 %__1
+}
+
+define i32 @AllocaA2Size4(i32 %n) {
+  %array = alloca i8, i32 4, align 2
+  %addr = ptrtoint i8* %array to i32
+  ret i32 %addr
+
+; CHECK:      __0:
+; CHECK-NEXT:   %__1 = alloca i8, i32 4, align 2
+; CHECK-NEXT:   ret i32 %__1
+}
+
+define i32 @AllocaA8Size4(i32 %n) {
+  %array = alloca i8, i32 4, align 8
+  %addr = ptrtoint i8* %array to i32
+  ret i32 %addr
+
+; CHECK:      __0:
+; CHECK-NEXT:   %__1 = alloca i8, i32 4, align 8
+; CHECK-NEXT:   ret i32 %__1
+}
+
+define i32 @Alloca16Size4(i32 %n) {
+  %array = alloca i8, i32 4, align 16
+  %addr = ptrtoint i8* %array to i32
+  ret i32 %addr
+
+; CHECK: __0:
+; CHECK-NEXT:   %__1 = alloca i8, i32 4, align 16
+; CHECK-NEXT:   ret i32 %__1
+}
+
+; Show examples where size is not known at compile time.
+
+define i32 @AllocaVarsizeA0(i32 %n) {
+  %array = alloca i8, i32 %n
+  %addr = ptrtoint i8* %array to i32
+  ret i32 %addr
+
+; CHECK: __0:
+; CHECK-NEXT:   %__1 = alloca i8, i32 %__0, align 0
+; CHECK-NEXT:   ret i32 %__1
+}
+
+define i32 @AllocaVarsizeA1(i32 %n) {
+  %array = alloca i8, i32 %n, align 1
+  %addr = ptrtoint i8* %array to i32
+  ret i32 %addr
+
+; CHECK:      __0:
+; CHECK-NEXT:   %__1 = alloca i8, i32 %__0, align 1
+; CHECK-NEXT:   ret i32 %__1
+}
+
+define i32 @AllocaVarsizeA2(i32 %n) {
+  %array = alloca i8, i32 %n, align 2
+  %addr = ptrtoint i8* %array to i32
+  ret i32 %addr
+
+; CHECK:      __0:
+; CHECK-NEXT:   %__1 = alloca i8, i32 %__0, align 2
+; CHECK-NEXT:   ret i32 %__1
+}
+
+define i32 @AllocaVarsizeA4(i32 %n) {
+  %array = alloca i8, i32 %n, align 4
+  %addr = ptrtoint i8* %array to i32
+  ret i32 %addr
+
+; CHECK:      __0:
+; CHECK-NEXT:   %__1 = alloca i8, i32 %__0, align 4
+; CHECK-NEXT:   ret i32 %__1
+}
+
+define i32 @AllocaVarsizeA8(i32 %n) {
+  %array = alloca i8, i32 %n, align 8
+  %addr = ptrtoint i8* %array to i32
+  ret i32 %addr
+
+; CHECK:      __0:
+; CHECK-NEXT:   %__1 = alloca i8, i32 %__0, align 8
+; CHECK-NEXT:   ret i32 %__1
+}
+
+define i32 @AllocaVarsizeA16(i32 %n) {
+  %array = alloca i8, i32 %n, align 16
+  %addr = ptrtoint i8* %array to i32
+  ret i32 %addr
+
+; CHECK:      __0:
+; CHECK-NEXT:   %__1 = alloca i8, i32 %__0, align 16
+; CHECK-NEXT:   ret i32 %__1
+}