X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=blobdiff_plain;f=test%2FTransforms%2FSimplifyCFG%2FX86%2Fswitch_to_lookup_table.ll;h=9cf57b38dfeb48bedc6b5944e8cf3fbc27821198;hp=5d9ecbf7077c22912257be2d8baecd453ad83ae8;hb=d5c2318adc7bde590d9f9369ef97fe7adde3f1a4;hpb=4646580bc8677def08ecd910839c18c06f82c049

diff --git a/test/Transforms/SimplifyCFG/X86/switch_to_lookup_table.ll b/test/Transforms/SimplifyCFG/X86/switch_to_lookup_table.ll
index 5d9ecbf7077..9cf57b38dfe 100644
--- a/test/Transforms/SimplifyCFG/X86/switch_to_lookup_table.ll
+++ b/test/Transforms/SimplifyCFG/X86/switch_to_lookup_table.ll
@@ -21,8 +21,8 @@ target triple = "x86_64-unknown-linux-gnu"
 ; The table for @cprop
 ; CHECK: @switch.table5 = private unnamed_addr constant [7 x i32] [i32 5, i32 42, i32 126, i32 -452, i32 128, i32 6, i32 7]
 
-; The table for @unreachable
-; CHECK: @switch.table6 = private unnamed_addr constant [5 x i32] [i32 0, i32 0, i32 0, i32 1, i32 -1]
+; The table for @unreachable_case
+; CHECK: @switch.table6 = private unnamed_addr constant [9 x i32] [i32 0, i32 0, i32 0, i32 2, i32 -1, i32 1, i32 1, i32 1, i32 1]
 
 ; A simple int-to-int selection switch.
 ; It is dense enough to be replaced by table lookup.
@@ -752,7 +752,7 @@ return:
 ; CHECK: %switch.gep = getelementptr inbounds [7 x i32]* @switch.table5, i32 0, i32 %switch.tableidx
 }
 
-define i32 @unreachable(i32 %x)  {
+define i32 @unreachable_case(i32 %x)  {
 entry:
   switch i32 %x, label %sw.default [
     i32 0, label %sw.bb
@@ -770,15 +770,15 @@ sw.bb: br label %return
 sw.bb1: unreachable
 sw.bb2: br label %return
 sw.bb3: br label %return
-sw.default: unreachable
+sw.default: br label %return
 
 return:
-  %retval.0 = phi i32 [ 1, %sw.bb3 ], [ -1, %sw.bb2 ], [ 0, %sw.bb ]
+  %retval.0 = phi i32 [ 1, %sw.bb3 ], [ -1, %sw.bb2 ], [ 0, %sw.bb ], [ 2, %sw.default ]
   ret i32 %retval.0
 
-; CHECK-LABEL: @unreachable(
+; CHECK-LABEL: @unreachable_case(
 ; CHECK: switch.lookup:
-; CHECK: getelementptr inbounds [5 x i32]* @switch.table6, i32 0, i32 %switch.tableidx
+; CHECK: getelementptr inbounds [9 x i32]* @switch.table6, i32 0, i32 %switch.tableidx
 }
 
 ; Don't create a table with illegal type
@@ -1077,3 +1077,170 @@ return:
 ; CHECK-NEXT: ret i8 %switch.idx.cast
 }
 
+; Reuse the inverted table range compare.
+define i32 @reuse_cmp1(i32 %x) {
+entry:
+  switch i32 %x, label %sw.default [
+    i32 0, label %sw.bb
+    i32 1, label %sw.bb1
+    i32 2, label %sw.bb2
+    i32 3, label %sw.bb3
+  ]
+sw.bb: br label %sw.epilog
+sw.bb1: br label %sw.epilog
+sw.bb2: br label %sw.epilog
+sw.bb3: br label %sw.epilog
+sw.default: br label %sw.epilog
+sw.epilog:
+  %r.0 = phi i32 [ 0, %sw.default ], [ 13, %sw.bb3 ], [ 12, %sw.bb2 ], [ 11, %sw.bb1 ], [ 10, %sw.bb ]
+  %cmp = icmp eq i32 %r.0, 0       ; This compare can be "replaced".
+  br i1 %cmp, label %if.then, label %if.end
+if.then: br label %return
+if.end: br label %return
+return:
+  %retval.0 = phi i32 [ 100, %if.then ], [ %r.0, %if.end ]
+  ret i32 %retval.0
+; CHECK-LABEL: @reuse_cmp1(
+; CHECK: entry:
+; CHECK-NEXT: %switch.tableidx = sub i32 %x, 0
+; CHECK-NEXT: [[C:%.+]] = icmp ult i32 %switch.tableidx, 4
+; CHECK-NEXT: %inverted.cmp = xor i1 [[C]], true
+; CHECK:      [[R:%.+]] = select i1 %inverted.cmp, i32 100, i32 {{.*}}
+; CHECK-NEXT: ret i32 [[R]]
+}
+
+; Reuse the table range compare.
+define i32 @reuse_cmp2(i32 %x) {
+entry:
+  switch i32 %x, label %sw.default [
+    i32 0, label %sw.bb
+    i32 1, label %sw.bb1
+    i32 2, label %sw.bb2
+    i32 3, label %sw.bb3
+  ]
+sw.bb: br label %sw.epilog
+sw.bb1: br label %sw.epilog
+sw.bb2: br label %sw.epilog
+sw.bb3: br label %sw.epilog
+sw.default: br label %sw.epilog
+sw.epilog:
+  %r.0 = phi i32 [ 4, %sw.default ], [ 3, %sw.bb3 ], [ 2, %sw.bb2 ], [ 1, %sw.bb1 ], [ 0, %sw.bb ]
+  %cmp = icmp ne i32 %r.0, 4       ; This compare can be "replaced".
+  br i1 %cmp, label %if.then, label %if.end
+if.then: br label %return
+if.end: br label %return
+return:
+  %retval.0 = phi i32 [ %r.0, %if.then ], [ 100, %if.end ]
+  ret i32 %retval.0
+; CHECK-LABEL: @reuse_cmp2(
+; CHECK: entry:
+; CHECK-NEXT: %switch.tableidx = sub i32 %x, 0
+; CHECK-NEXT: [[C:%.+]] = icmp ult i32 %switch.tableidx, 4
+; CHECK:      [[R:%.+]] = select i1 [[C]], i32 {{.*}}, i32 100
+; CHECK-NEXT: ret i32 [[R]]
+}
+
+; Cannot reuse the table range compare, because the default value is the same
+; as one of the case values.
+define i32 @no_reuse_cmp(i32 %x) {
+entry:
+  switch i32 %x, label %sw.default [
+    i32 0, label %sw.bb
+    i32 1, label %sw.bb1
+    i32 2, label %sw.bb2
+    i32 3, label %sw.bb3
+  ]
+sw.bb: br label %sw.epilog
+sw.bb1: br label %sw.epilog
+sw.bb2: br label %sw.epilog
+sw.bb3: br label %sw.epilog
+sw.default: br label %sw.epilog
+sw.epilog:
+  %r.0 = phi i32 [ 12, %sw.default ], [ 13, %sw.bb3 ], [ 12, %sw.bb2 ], [ 11, %sw.bb1 ], [ 10, %sw.bb ]
+  %cmp = icmp ne i32 %r.0, 0
+  br i1 %cmp, label %if.then, label %if.end
+if.then: br label %return
+if.end: br label %return
+return:
+  %retval.0 = phi i32 [ %r.0, %if.then ], [ 100, %if.end ]
+  ret i32 %retval.0
+; CHECK-LABEL: @no_reuse_cmp(
+; CHECK:  [[S:%.+]] = select 
+; CHECK-NEXT:  %cmp = icmp ne i32 [[S]], 0
+; CHECK-NEXT:  [[R:%.+]] = select i1 %cmp, i32 [[S]], i32 100
+; CHECK-NEXT:  ret i32 [[R]]
+}
+
+; Cannot reuse the table range compare, because the phi at the switch merge
+; point is not dominated by the switch.
+define i32 @no_reuse_cmp2(i32 %x, i32 %y) {
+entry:
+  %ec = icmp ne i32 %y, 0
+  br i1 %ec, label %switch.entry, label %sw.epilog
+switch.entry:
+  switch i32 %x, label %sw.default [
+    i32 0, label %sw.bb
+    i32 1, label %sw.bb1
+    i32 2, label %sw.bb2
+    i32 3, label %sw.bb3
+  ]
+sw.bb: br label %sw.epilog
+sw.bb1: br label %sw.epilog
+sw.bb2: br label %sw.epilog
+sw.bb3: br label %sw.epilog
+sw.default: br label %sw.epilog
+sw.epilog:
+  %r.0 = phi i32 [100, %entry], [ 0, %sw.default ], [ 13, %sw.bb3 ], [ 12, %sw.bb2 ], [ 11, %sw.bb1 ], [ 10, %sw.bb ]
+  %cmp = icmp eq i32 %r.0, 0       ; This compare can be "replaced".
+  br i1 %cmp, label %if.then, label %if.end
+if.then: br label %return
+if.end: br label %return
+return:
+  %retval.0 = phi i32 [ 100, %if.then ], [ %r.0, %if.end ]
+  ret i32 %retval.0
+; CHECK-LABEL: @no_reuse_cmp2(
+; CHECK:  %r.0 = phi
+; CHECK-NEXT:  %cmp = icmp eq i32 %r.0, 0
+; CHECK-NEXT:  [[R:%.+]] = select i1 %cmp
+; CHECK-NEXT:  ret i32 [[R]]
+}
+
+define void @pr20210(i8 %x, i1 %y) {
+; %z has uses outside of its BB or the phi it feeds into,
+; so doing a table lookup and jumping directly to while.cond would
+; cause %z to cease dominating all its uses.
+
+entry:
+  br i1 %y, label %sw, label %intermediate
+
+sw:
+  switch i8 %x, label %end [
+    i8 7, label %intermediate
+    i8 3, label %intermediate
+    i8 2, label %intermediate
+    i8 1, label %intermediate
+    i8 0, label %intermediate
+  ]
+
+intermediate:
+  %z = zext i8 %x to i32
+  br label %while.cond
+
+while.cond:
+  %i = phi i32 [ %z, %intermediate ], [ %j, %while.body ]
+  %b = icmp ne i32 %i, 7
+  br i1 %b, label %while.body, label %while.end
+
+while.body:
+  %j = add i32 %i, 1
+  br label %while.cond
+
+while.end:
+  call void @exit(i32 %z)
+  unreachable
+
+end:
+  ret void
+; CHECK-LABEL: @pr20210
+; CHECK: switch i8 %x
+}