From 682e4aa034649aa38ea7a4996e16c97dd7ad0030 Mon Sep 17 00:00:00 2001 From: Evan Cheng Date: Thu, 10 Apr 2008 02:32:10 +0000 Subject: Teach branch folding pass about implicit_def instructions. Unfortunately we can't just eliminate them since register scavenger expects every register use to be defined. However, we can delete them when there are no intra-block uses. Carefully removing some implicit def's which enable more blocks to be optimized away. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49461 91177308-0d34-0410-b5e6-96231b3b80d8 --- test/CodeGen/X86/2008-04-09-BranchFolding.ll | 48 ++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 test/CodeGen/X86/2008-04-09-BranchFolding.ll (limited to 'test/CodeGen/X86/2008-04-09-BranchFolding.ll') diff --git a/test/CodeGen/X86/2008-04-09-BranchFolding.ll b/test/CodeGen/X86/2008-04-09-BranchFolding.ll new file mode 100644 index 0000000..fea54c4 --- /dev/null +++ b/test/CodeGen/X86/2008-04-09-BranchFolding.ll @@ -0,0 +1,48 @@ +; RUN: llvm-as < %s | llc -march=x86 | not grep jmp + + %struct..0anon = type { i32 } + %struct.binding_level = type { %struct.tree_node*, %struct.tree_node*, %struct.tree_node*, %struct.tree_node*, %struct.tree_node*, %struct.binding_level*, i8, i8, i8, i8, i8, i32, %struct.tree_node* } + %struct.lang_decl = type opaque + %struct.rtx_def = type { i16, i8, i8, [1 x %struct..0anon] } + %struct.tree_decl = type { [12 x i8], i8*, i32, %struct.tree_node*, i32, i8, i8, i8, i8, %struct.tree_node*, %struct.tree_node*, %struct.tree_node*, %struct.tree_node*, %struct.tree_node*, %struct.tree_node*, %struct.tree_node*, %struct.tree_node*, %struct.tree_node*, %struct.rtx_def*, %struct..0anon, { %struct.rtx_def* }, %struct.tree_node*, %struct.lang_decl* } + %struct.tree_node = type { %struct.tree_decl } + +define fastcc %struct.tree_node* @pushdecl(%struct.tree_node* %x) nounwind { +entry: + %tmp3.i40 = icmp eq %struct.binding_level* null, null ; [#uses=2] + br i1 false, label %bb143, label %bb140 +bb140: ; preds = %entry + br i1 %tmp3.i40, label %bb160, label %bb17.i +bb17.i: ; preds = %bb140 + ret %struct.tree_node* null +bb143: ; preds = %entry + %tmp8.i43 = load %struct.tree_node** null, align 4 ; <%struct.tree_node*> [#uses=1] + br i1 %tmp3.i40, label %bb160, label %bb9.i48 +bb9.i48: ; preds = %bb143 + ret %struct.tree_node* null +bb160: ; preds = %bb143, %bb140 + %t.0.reg2mem.0 = phi %struct.tree_node* [ null, %bb140 ], [ %tmp8.i43, %bb143 ] ; <%struct.tree_node*> [#uses=1] + %tmp162 = icmp eq %struct.tree_node* %t.0.reg2mem.0, null ; [#uses=2] + br i1 %tmp162, label %bb174, label %bb165 +bb165: ; preds = %bb160 + br label %bb174 +bb174: ; preds = %bb165, %bb160 + %line.0 = phi i32 [ 0, %bb165 ], [ undef, %bb160 ] ; [#uses=1] + %file.0 = phi i8* [ null, %bb165 ], [ undef, %bb160 ] ; [#uses=1] + br i1 %tmp162, label %bb344, label %bb73.i +bb73.i: ; preds = %bb174 + br i1 false, label %bb226.i, label %bb220.i +bb220.i: ; preds = %bb73.i + ret %struct.tree_node* null +bb226.i: ; preds = %bb73.i + br i1 false, label %bb260, label %bb273.i +bb273.i: ; preds = %bb226.i + ret %struct.tree_node* null +bb260: ; preds = %bb226.i + tail call void (i8*, i32, ...)* @pedwarn_with_file_and_line( i8* %file.0, i32 %line.0, i8* null ) nounwind + ret %struct.tree_node* null +bb344: ; preds = %bb174 + ret %struct.tree_node* null +} + +declare void @pedwarn_with_file_and_line(i8*, i32, ...) nounwind -- cgit v1.1