1 files changed, 95 insertions, 0 deletions
diff --git a/test/Transforms/CodeGenPrepare/X86/widen_switch.ll b/test/Transforms/CodeGenPrepare/X86/widen_switch.ll
new file mode 100644
index 000000000000..53c9cc073558
--- /dev/null
+++ b/test/Transforms/CodeGenPrepare/X86/widen_switch.ll
@@ -0,0 +1,95 @@
+;; x86 is chosen to show the transform when 8-bit and 16-bit registers are available.
+
+; RUN: opt < %s -codegenprepare -S -mtriple=x86_64-unknown-unknown    | FileCheck %s --check-prefix=X86
+
+; No change for x86 because 16-bit registers are part of the architecture.
+
+define i32 @widen_switch_i16(i32 %a)  {
+entry:
+  %trunc = trunc i32 %a to i16
+  switch i16 %trunc, label %sw.default [
+    i16 1, label %sw.bb0
+    i16 -1, label %sw.bb1
+  ]
+
+sw.bb0:
+  br label %return
+
+sw.bb1:
+  br label %return
+
+sw.default:
+  br label %return
+
+return:
+  %retval = phi i32 [ -1, %sw.default ], [ 0, %sw.bb0 ], [ 1, %sw.bb1 ]
+  ret i32 %retval
+
+; X86-LABEL: @widen_switch_i16(
+; X86:       %trunc = trunc i32 %a to i16
+; X86-NEXT:  switch i16 %trunc, label %sw.default [
+; X86-NEXT:    i16 1, label %return
+; X86-NEXT:    i16 -1, label %sw.bb1
+}
+
+; Widen to 32-bit from a smaller, non-native type.
+
+define i32 @widen_switch_i17(i32 %a)  {
+entry:
+  %trunc = trunc i32 %a to i17
+  switch i17 %trunc, label %sw.default [
+    i17 10, label %sw.bb0
+    i17 -1, label %sw.bb1
+  ]
+
+sw.bb0:
+  br label %return
+
+sw.bb1:
+  br label %return
+
+sw.default:
+  br label %return
+
+return:
+  %retval = phi i32 [ -1, %sw.default ], [ 0, %sw.bb0 ], [ 1, %sw.bb1 ]
+  ret i32 %retval
+
+; X86-LABEL: @widen_switch_i17(
+; X86:       %0 = zext i17 %trunc to i32
+; X86-NEXT:  switch i32 %0, label %sw.default [
+; X86-NEXT:    i32 10, label %return
+; X86-NEXT:    i32 131071, label %sw.bb1
+}
+
+; If the switch condition is a sign-extended function argument, then the
+; condition and cases should be sign-extended rather than zero-extended
+; because the sign-extension can be optimized away.
+
+define i32 @widen_switch_i16_sext(i2 signext %a)  {
+entry:
+  switch i2 %a, label %sw.default [
+    i2 1, label %sw.bb0
+    i2 -1, label %sw.bb1
+  ]
+
+sw.bb0:
+  br label %return
+
+sw.bb1:
+  br label %return
+
+sw.default:
+  br label %return
+
+return:
+  %retval = phi i32 [ -1, %sw.default ], [ 0, %sw.bb0 ], [ 1, %sw.bb1 ]
+  ret i32 %retval
+
+; X86-LABEL: @widen_switch_i16_sext(
+; X86:       %0 = sext i2 %a to i8
+; X86-NEXT:  switch i8 %0, label %sw.default [
+; X86-NEXT:    i8 1, label %return
+; X86-NEXT:    i8 -1, label %sw.bb1
+}
+