[InstCombine] Add test cases demonstrating failure to handle (select (icmp eq (and...

InstCombine has an optimization that recognizes an and with the sign bit of legal type size and turns it into a truncate and compare that checks the sign bit. But the select handling code doesn't recognize this idiom.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@305338 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/Transforms/InstCombine/select-with-bitwise-ops.ll b/test/Transforms/InstCombine/select-with-bitwise-ops.ll
index 68b73af21a8d6057caa1cb438e85aebe5ecd38d5..55ba730599dddfa6fac463aaf21122654c1812b8 100644 (file)
--- a/test/Transforms/InstCombine/select-with-bitwise-ops.ll
+++ b/test/Transforms/InstCombine/select-with-bitwise-ops.ll
@@ -1,6 +1,8 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt < %s -instcombine -S | FileCheck %s
 
+target datalayout = "n8:16:32:64"
+
 define i32 @select_icmp_eq_and_1_0_or_2(i32 %x, i32 %y) {
 ; CHECK-LABEL: @select_icmp_eq_and_1_0_or_2(
 ; CHECK-NEXT:    [[AND:%.*]] = shl i32 %x, 1
@@ -295,3 +297,32 @@ define i32 @test67(i16 %x) {
   ret i32 %3
 }
 
+define i32 @test68(i32 %x, i32 %y) {
+; CHECK-LABEL: @test68(
+; CHECK-NEXT:    [[TMP1:%.*]] = trunc i32 [[X:%.*]] to i8
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[TMP1]], -1
+; CHECK-NEXT:    [[OR:%.*]] = or i32 [[Y:%.*]], 2
+; CHECK-NEXT:    [[SELECT:%.*]] = select i1 [[CMP]], i32 [[Y]], i32 [[OR]]
+; CHECK-NEXT:    ret i32 [[SELECT]]
+;
+  %and = and i32 %x, 128
+  %cmp = icmp eq i32 %and, 0
+  %or = or i32 %y, 2
+  %select = select i1 %cmp, i32 %y, i32 %or
+  ret i32 %select
+}
+
+define i32 @test69(i32 %x, i32 %y) {
+; CHECK-LABEL: @test69(
+; CHECK-NEXT:    [[TMP1:%.*]] = trunc i32 [[X:%.*]] to i8
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i8 [[TMP1]], 0
+; CHECK-NEXT:    [[OR:%.*]] = or i32 [[Y:%.*]], 2
+; CHECK-NEXT:    [[SELECT:%.*]] = select i1 [[CMP]], i32 [[Y]], i32 [[OR]]
+; CHECK-NEXT:    ret i32 [[SELECT]]
+;
+  %and = and i32 %x, 128
+  %cmp = icmp ne i32 %and, 0
+  %or = or i32 %y, 2
+  %select = select i1 %cmp, i32 %y, i32 %or
+  ret i32 %select
+}