Add switch instruction to Subzero bitcode reader.

tests_lit/reader_tests/switch.ll

+; Test switch 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 @testSwitch(i32 %a) {

[Jim Stichnoth, 2014/09/17 20:18:20]

I think it wouldn't hurt to have a test where there are no case labels except
the default.

[Karl, 2014/09/17 22:07:19]

Done.

+entry:
+  switch i32 %a, label %sw.default [
+    i32 1, label %sw.epilog
+    i32 2, label %sw.epilog
+    i32 3, label %sw.epilog
+    i32 7, label %sw.bb1
+    i32 8, label %sw.bb1
+    i32 15, label %sw.bb2
+    i32 14, label %sw.bb2
+  ]
+
+sw.default:                                       ; preds = %entry
+  %add = add i32 %a, 27
+  br label %sw.epilog
+
+sw.bb1:                                           ; preds = %entry, %entry
+  %phitmp = sub i32 21, %a
+  br label %sw.bb2
+
+sw.bb2:                                           ; preds = %sw.bb1, %entry, %entry
+  %result.0 = phi i32 [ 1, %entry ], [ 1, %entry ], [ %phitmp, %sw.bb1 ]
+  br label %sw.epilog
+
+sw.epilog:                                        ; preds = %sw.bb2, %sw.default, %entry, %entry, %entry
+  %result.1 = phi i32 [ %add, %sw.default ], [ %result.0, %sw.bb2 ], [ 17, %entry ], [ 17, %entry ], [ 17, %entry ]
+  ret i32 %result.1
+}
+
+; CHECK:      define i32 @testSwitch(i32 %a) {
+; CHECK-NEXT: entry:
+; CHECK-NEXT:   switch i32 %a, label %sw.default [
+; CHECK-NEXT:     i32 1, label %sw.epilog
+; CHECK-NEXT:     i32 2, label %sw.epilog
+; CHECK-NEXT:     i32 3, label %sw.epilog
+; CHECK-NEXT:     i32 7, label %sw.bb1
+; CHECK-NEXT:     i32 8, label %sw.bb1
+; CHECK-NEXT:     i32 15, label %sw.bb2
+; CHECK-NEXT:     i32 14, label %sw.bb2
+; CHECK-NEXT:   ]
+; CHECK-NEXT: sw.default:
+; CHECK-NEXT:   %add = add i32 %a, 27
+; CHECK-NEXT:   br label %sw.epilog
+; CHECK-NEXT: sw.bb1:
+; CHECK-NEXT:   %phitmp = sub i32 21, %a
+; CHECK-NEXT:   br label %sw.bb2
+; CHECK-NEXT: sw.bb2:
+; CHECK-NEXT:   %result.0 = phi i32 [ 1, %entry ], [ 1, %entry ], [ %phitmp, %sw.bb1 ]
+; CHECK-NEXT:   br label %sw.epilog
+; CHECK-NEXT: sw.epilog:
+; CHECK-NEXT:   %result.1 = phi i32 [ %add, %sw.default ], [ %result.0, %sw.bb2 ], [ 17, %entry ], [ 17, %entry ], [ 17, %entry ]
+; CHECK-NEXT:   ret i32 %result.1
+; CHECK-NEXT: }
+
+define void @testSignedI32Values(i32 %a) {

[Jim Stichnoth, 2014/09/17 20:18:20]

Add tests for i64 as well.

[Karl, 2014/09/17 22:07:19]

Done.

+entry:
+  switch i32 %a, label %labelDefault [
+  i32 0, label %label0
+  i32 -1, label %labelM1
+  i32 3, label %labelOther
+  i32 -3, label %labelOther
+  i32 -2147483648, label %labelMin  ; min signed i32
+  i32 2147483647, label %labelMax   ; max signed i32
+  ]
+labelDefault:
+  ret void
+label0:
+  ret void
+labelM1:
+  ret void
+labelMin:
+  ret void
+labelMax:
+  ret void
+labelOther:
+  ret void
+}
+; CHECK-NEXT: define void @testSignedI32Values(i32 %a) {
+; CHECK-NEXT: entry:
+; CHECK-NEXT:   switch i32 %a, label %labelDefault [
+; CHECK-NEXT:     i32 0, label %label0
+; CHECK-NEXT:     i32 -1, label %labelM1
+; CHECK-NEXT:     i32 3, label %labelOther
+; CHECK-NEXT:     i32 -3, label %labelOther
+; CHECK-NEXT:     i32 -2147483648, label %labelMin
+; CHECK-NEXT:     i32 2147483647, label %labelMax
+; CHECK-NEXT:   ]
+; CHECK-NEXT: labelDefault:
+; CHECK-NEXT:   ret void
+; CHECK-NEXT: label0:
+; CHECK-NEXT:   ret void
+; CHECK-NEXT: labelM1:
+; CHECK-NEXT:   ret void
+; CHECK-NEXT: labelMin:
+; CHECK-NEXT:   ret void
+; CHECK-NEXT: labelMax:
+; CHECK-NEXT:   ret void
+; CHECK-NEXT: labelOther:
+; CHECK-NEXT:   ret void
+; CHECK-NEXT: }
+
+define void @testUnsignedI32Values(i32 %a) {
+entry:
+  switch i32 %a, label %exit [
+  i32 0, label %exit
+  i32 2147483647, label %exit   ; max signed i32

[Jim Stichnoth, 2014/09/17 20:18:20]

For this and the I16 and I8 unsigned tests (and the TBD I64 test), I would feel
warmer and fuzzier if you also tested max_signed+1.

[Karl, 2014/09/17 22:07:19]

Done.

+  i32 4294967295, label %exit   ; max unsigned i32
+  ]
+exit:
+  ret void
+}
+
+; CHECK-NEXT: define void @testUnsignedI32Values(i32 %a) {
+; CHECK-NEXT: entry:
+; CHECK-NEXT:   switch i32 %a, label %exit [
+; CHECK-NEXT:     i32 0, label %exit
+; CHECK-NEXT:     i32 2147483647, label %exit
+;                 ; Note that -1 is signed version of 4294967295
+; CHECK-NEXT:     i32 -1, label %exit
+; CHECK-NEXT:   ]
+; CHECK-NEXT: exit:
+; CHECK-NEXT:   ret void
+; CHECK-NEXT: }
+
+define void @testSignedI16Values(i32 %p) {
+entry:
+  %a = trunc i32 %p to i16
+  switch i16 %a, label %exit [
+  i16 0, label %exit
+  i16 -1, label %exit
+  i16 3, label %exit
+  i16 -3, label %exit
+  i16 -32768, label %exit   ; min signed i16
+  i16 32767, label %exit   ; max unsigned i16
+  ]
+exit:
+  ret void
+}
+
+; CHECK-NEXT: define void @testSignedI16Values(i32 %p) {
+; CHECK-NEXT: entry:
+; CHECK-NEXT:   %a = trunc i32 %p to i16
+; CHECK-NEXT:   switch i16 %a, label %exit [
+; CHECK-NEXT:     i16 0, label %exit
+; CHECK-NEXT:     i16 -1, label %exit
+; CHECK-NEXT:     i16 3, label %exit
+; CHECK-NEXT:     i16 -3, label %exit
+; CHECK-NEXT:     i16 -32768, label %exit
+; CHECK-NEXT:     i16 32767, label %exit
+; CHECK-NEXT:   ]
+; CHECK-NEXT: exit:
+; CHECK-NEXT:   ret void
+; CHECK-NEXT: }
+
+define void @testUnsignedI16Values(i32 %p) {
+entry:
+  %a = trunc i32 %p to i16
+  switch i16 %a, label %exit [
+  i16 0, label %exit
+  i16 32767, label %exit   ; max signed i16
+  i16 65535, label %exit   ; max unsigned i16
+  ]
+exit:
+  ret void
+}
+
+; CHECK-NEXT: define void @testUnsignedI16Values(i32 %p) {
+; CHECK-NEXT: entry:
+; CHECK-NEXT:   %a = trunc i32 %p to i16
+; CHECK-NEXT:   switch i16 %a, label %exit [
+; CHECK-NEXT:     i16 0, label %exit
+; CHECK-NEXT:     i16 32767, label %exit
+;                 ; Note that -1 is signed version of 65535
+; CHECK-NEXT:     i16 -1, label %exit
+; CHECK-NEXT:   ]
+; CHECK-NEXT: exit:
+; CHECK-NEXT:   ret void
+; CHECK-NEXT: }
+
+define void @testSignedI8Values(i32 %p) {
+entry:
+  %a = trunc i32 %p to i8
+  switch i8 %a, label %exit [
+  i8 0, label %exit
+  i8 -1, label %exit
+  i8 3, label %exit
+  i8 -3, label %exit
+  i8 -128, label %exit   ; min signed i8
+  i8 127, label %exit   ; max unsigned i8
+  ]
+exit:
+  ret void
+}
+
+; CHECK-NEXT: define void @testSignedI8Values(i32 %p) {
+; CHECK-NEXT: entry:
+; CHECK-NEXT:   %a = trunc i32 %p to i8
+; CHECK-NEXT:   switch i8 %a, label %exit [
+; CHECK-NEXT:     i8 0, label %exit
+; CHECK-NEXT:     i8 -1, label %exit
+; CHECK-NEXT:     i8 3, label %exit
+; CHECK-NEXT:     i8 -3, label %exit
+; CHECK-NEXT:     i8 -128, label %exit
+; CHECK-NEXT:     i8 127, label %exit
+; CHECK-NEXT:   ]
+; CHECK-NEXT: exit:
+; CHECK-NEXT:   ret void
+; CHECK-NEXT: }
+
+define void @testUnsignedI8Values(i32 %p) {
+entry:
+  %a = trunc i32 %p to i8
+  switch i8 %a, label %exit [
+  i8 0, label %exit
+  i8 127, label %exit   ; max signed i8
+  i8 255, label %exit   ; max unsigned i8
+  ]
+exit:
+  ret void
+}
+
+; CHECK-NEXT: define void @testUnsignedI8Values(i32 %p) {
+; CHECK-NEXT: entry:
+; CHECK-NEXT:   %a = trunc i32 %p to i8
+; CHECK-NEXT:   switch i8 %a, label %exit [
+; CHECK-NEXT:     i8 0, label %exit
+; CHECK-NEXT:     i8 127, label %exit
+;                 ; Note that -1 is signed version of 255
+; CHECK-NEXT:     i8 -1, label %exit
+; CHECK-NEXT:   ]
+; CHECK-NEXT: exit:
+; CHECK-NEXT:   ret void
+; CHECK-NEXT: }
+
+define void @testI1Values(i32 %p) {
+entry:
+  %a = trunc i32 %p to i1
+  switch i1 %a, label %exit [
+  i1 true, label %exit
+  i1 false, label %exit
+  ]
+exit:
+  ret void
+}
+
+; CHECK-NEXT: define void @testI1Values(i32 %p) {
+; CHECK-NEXT: entry:
+; CHECK-NEXT:   %a = trunc i32 %p to i1
+; CHECK-NEXT:   switch i1 %a, label %exit [
+; CHECK-NEXT:     i1 -1, label %exit
+; CHECK-NEXT:     i1 0, label %exit
+; CHECK-NEXT:   ]
+; CHECK-NEXT: exit:
+; CHECK-NEXT:   ret void
+; CHECK-NEXT: }