diff options
Diffstat (limited to 'test/Transforms/SimplifyCFG/X86/switch_to_lookup_table.ll')
| -rw-r--r-- | test/Transforms/SimplifyCFG/X86/switch_to_lookup_table.ll | 211 |
1 files changed, 203 insertions, 8 deletions
diff --git a/test/Transforms/SimplifyCFG/X86/switch_to_lookup_table.ll b/test/Transforms/SimplifyCFG/X86/switch_to_lookup_table.ll index fc22e7e..ea3b575 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 @@ -770,19 +770,47 @@ 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 +} + +define i32 @unreachable_default(i32 %x) { +entry: + switch i32 %x, label %default [ + i32 0, label %bb0 + i32 1, label %bb1 + i32 2, label %bb2 + i32 3, label %bb3 + ] + +bb0: br label %return +bb1: br label %return +bb2: br label %return +bb3: br label %return +default: unreachable + +return: + %retval = phi i32 [ 42, %bb0 ], [ 52, %bb1 ], [ 1, %bb2 ], [ 2, %bb3 ] + ret i32 %retval + +; CHECK-LABEL: @unreachable_default( +; CHECK: entry: +; CHECK-NEXT: %switch.tableidx = sub i32 %x, 0 +; CHECK-NOT: icmp +; CHECK-NOT: br 1i +; CHECK-NEXT: %switch.gep = getelementptr inbounds [4 x i32]* @switch.table7, i32 0, i32 %switch.tableidx +; CHECK-NEXT: %switch.load = load i32* %switch.gep +; CHECK-NEXT: ret i32 %switch.load } ; Don't create a table with illegal type -; rdar://12779436 define i96 @illegaltype(i32 %c) { entry: switch i32 %c, label %sw.default [ @@ -1078,3 +1106,170 @@ 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 +} |