Add alloca instruction to Subzero bitcode reader.

tests_lit/reader_tests/alloc.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
+

[Karl, 2014/09/08 21:16:23]

Added case of alignment == 0, since it is allowed.

+define i32 @AllocaA1(i32 %n) {
+  %array = alloca i8, i32 %n, align 1
+  %addr = ptrtoint i8* %array to i32
+  ret i32 %addr
+}
+
+; CHECK:      define i32 @AllocaA1(i32 %__0) {
+; CHECK-NEXT: __0:
+; CHECK-NEXT:   %__1 = alloca i8, i32 %__0, align 1
+; CHECK-NEXT:   ret i32 %__1
+; CHECK-NEXT: }
+
+define i32 @AllocaA2(i32 %n) {
+  %array = alloca i8, i32 %n, align 2
+  %addr = ptrtoint i8* %array to i32
+  ret i32 %addr
+}
+
+; CHECK-NEXT: define i32 @AllocaA2(i32 %__0) {
+; CHECK-NEXT: __0:
+; CHECK-NEXT:   %__1 = alloca i8, i32 %__0, align 2
+; CHECK-NEXT:   ret i32 %__1
+; CHECK-NEXT: }
+
+define i32 @AllocaA4(i32 %n) {
+  %array = alloca i8, i32 %n, align 4
+  %addr = ptrtoint i8* %array to i32
+  ret i32 %addr
+}
+
+; CHECK-NEXT: define i32 @AllocaA4(i32 %__0) {
+; CHECK-NEXT: __0:
+; CHECK-NEXT:   %__1 = alloca i8, i32 %__0, align 4
+; CHECK-NEXT:   ret i32 %__1
+; CHECK-NEXT: }
+
+define i32 @AllocaA8(i32 %n) {
+  %array = alloca i8, i32 %n, align 8
+  %addr = ptrtoint i8* %array to i32
+  ret i32 %addr
+}
+
+; CHECK-NEXT: define i32 @AllocaA8(i32 %__0) {
+; CHECK-NEXT: __0:
+; CHECK-NEXT:   %__1 = alloca i8, i32 %__0, align 8
+; CHECK-NEXT:   ret i32 %__1
+; CHECK-NEXT: }
+
+define i32 @AllocaA16(i32 %n) {
+  %array = alloca i8, i32 %n, align 16

[jvoung (off chromium), 2014/09/05 16:55:04]

Once you have the constants block would be good to have a test for the constant
case, since that's the more typical use of alloca.

[Karl, 2014/09/08 21:16:23]

Done.

+  %addr = ptrtoint i8* %array to i32
+  ret i32 %addr
+}
+
+; CHECK-NEXT: define i32 @AllocaA16(i32 %__0) {
+; CHECK-NEXT: __0:
+; CHECK-NEXT:   %__1 = alloca i8, i32 %__0, align 16
+; CHECK-NEXT:   ret i32 %__1
+; CHECK-NEXT: }