[llvm-commits] [llvm] r51394 - in /llvm/trunk: lib/CodeGen/SimpleRegisterCoalescing.cpp test/CodeGen/X86/2008-05-21-CoalescerBug.ll
Evan Cheng
evan.cheng at apple.com
Wed May 21 15:34:14 PDT 2008
Author: evancheng
Date: Wed May 21 17:34:12 2008
New Revision: 51394
URL: http://llvm.org/viewvc/llvm-project?rev=51394&view=rev
Log:
Fix PR2343. An *interesting* coalescer bug.
BB1:
vr1025 = copy vr1024
..
BB2:
vr1024 = op
= op vr1025
<loop eventually branch back to BB1>
Even though vr1025 is copied from vr1024, it's not safe to coalesced them since live range of vr1025 intersects the def of vr1024. This happens when vr1025 is assigned the value of the previous iteration of vr1024 in the loop.
Added:
llvm/trunk/test/CodeGen/X86/2008-05-21-CoalescerBug.ll
Modified:
llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp
Modified: llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp?rev=51394&r1=51393&r2=51394&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp (original)
+++ llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp Wed May 21 17:34:12 2008
@@ -1322,7 +1322,20 @@
// Copy from the RHS?
if (!RangeIsDefinedByCopyFromReg(LHS, LHSIt, RHS.reg))
return false; // Nope, bail out.
-
+
+ if (LHSIt->contains(RHSIt->valno->def))
+ // Here is an interesting situation:
+ // BB1:
+ // vr1025 = copy vr1024
+ // ..
+ // BB2:
+ // vr1024 = op
+ // = vr1025
+ // Even though vr1025 is copied from vr1024, it's not safe to
+ // coalesced them since live range of vr1025 intersects the
+ // def of vr1024. This happens because vr1025 is assigned the
+ // value of the previous iteration of vr1024.
+ return false;
EliminatedLHSVals.push_back(LHSIt->valno);
}
@@ -1348,6 +1361,19 @@
// Otherwise, if this is a copy from the RHS, mark it as being merged
// in.
if (RangeIsDefinedByCopyFromReg(LHS, LHSIt, RHS.reg)) {
+ if (LHSIt->contains(RHSIt->valno->def))
+ // Here is an interesting situation:
+ // BB1:
+ // vr1025 = copy vr1024
+ // ..
+ // BB2:
+ // vr1024 = op
+ // = vr1025
+ // Even though vr1025 is copied from vr1024, it's not safe to
+ // coalesced them since live range of vr1025 intersects the
+ // def of vr1024. This happens because vr1025 is assigned the
+ // value of the previous iteration of vr1024.
+ return false;
EliminatedLHSVals.push_back(LHSIt->valno);
// We know this entire LHS live range is okay, so skip it now.
Added: llvm/trunk/test/CodeGen/X86/2008-05-21-CoalescerBug.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/2008-05-21-CoalescerBug.ll?rev=51394&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/2008-05-21-CoalescerBug.ll (added)
+++ llvm/trunk/test/CodeGen/X86/2008-05-21-CoalescerBug.ll Wed May 21 17:34:12 2008
@@ -0,0 +1,97 @@
+; RUN: llvm-as < %s | llc -march=x86 -fast | grep mov | count 4
+; PR2343
+
+ %llvm.dbg.anchor.type = type { i32, i32 }
+ %struct.CUMULATIVE_ARGS = type { i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }
+ %struct.VEC_basic_block_base = type { i32, i32, [1 x %struct.basic_block_def*] }
+ %struct.VEC_basic_block_gc = type { %struct.VEC_basic_block_base }
+ %struct.VEC_edge_base = type { i32, i32, [1 x %struct.edge_def*] }
+ %struct.VEC_edge_gc = type { %struct.VEC_edge_base }
+ %struct.VEC_rtx_base = type { i32, i32, [1 x %struct.rtx_def*] }
+ %struct.VEC_rtx_gc = type { %struct.VEC_rtx_base }
+ %struct.VEC_temp_slot_p_base = type { i32, i32, [1 x %struct.temp_slot*] }
+ %struct.VEC_temp_slot_p_gc = type { %struct.VEC_temp_slot_p_base }
+ %struct.VEC_tree_base = type { i32, i32, [1 x %struct.tree_node*] }
+ %struct.VEC_tree_gc = type { %struct.VEC_tree_base }
+ %struct.__sbuf = type { i8*, i32 }
+ %struct._obstack_chunk = type { i8*, %struct._obstack_chunk*, [4 x i8] }
+ %struct.basic_block_def = type { %struct.tree_node*, %struct.VEC_edge_gc*, %struct.VEC_edge_gc*, i8*, %struct.loop*, [2 x %struct.et_node*], %struct.basic_block_def*, %struct.basic_block_def*, %struct.basic_block_il_dependent, %struct.tree_node*, %struct.edge_prediction*, i64, i32, i32, i32, i32 }
+ %struct.basic_block_il_dependent = type { %struct.rtl_bb_info* }
+ %struct.bitmap_element_def = type { %struct.bitmap_element_def*, %struct.bitmap_element_def*, i32, [4 x i32] }
+ %struct.bitmap_head_def = type { %struct.bitmap_element_def*, %struct.bitmap_element_def*, i32, %struct.bitmap_obstack* }
+ %struct.bitmap_obstack = type { %struct.bitmap_element_def*, %struct.bitmap_head_def*, %struct.obstack }
+ %struct.block_symbol = type { [3 x %struct.cfg_stats_d], %struct.object_block*, i64 }
+ %struct.cfg_stats_d = type { i32 }
+ %struct.control_flow_graph = type { %struct.basic_block_def*, %struct.basic_block_def*, %struct.VEC_basic_block_gc*, i32, i32, i32, %struct.VEC_basic_block_gc*, i32 }
+ %struct.def_optype_d = type { %struct.def_optype_d*, %struct.tree_node** }
+ %struct.edge_def = type { %struct.basic_block_def*, %struct.basic_block_def*, %struct.edge_def_insns, i8*, %struct.__sbuf*, i32, i32, i64, i32 }
+ %struct.edge_def_insns = type { %struct.rtx_def* }
+ %struct.edge_prediction = type { %struct.edge_prediction*, %struct.edge_def*, i32, i32 }
+ %struct.eh_status = type opaque
+ %struct.emit_status = type { i32, i32, %struct.rtx_def*, %struct.rtx_def*, %struct.sequence_stack*, i32, %struct.__sbuf, i32, i8*, %struct.rtx_def** }
+ %struct.et_node = type opaque
+ %struct.expr_status = type { i32, i32, i32, %struct.rtx_def*, %struct.rtx_def*, %struct.rtx_def* }
+ %struct.function = type { %struct.eh_status*, %struct.expr_status*, %struct.emit_status*, %struct.varasm_status*, %struct.control_flow_graph*, %struct.tree_node*, %struct.function*, i32, i32, i32, i32, %struct.rtx_def*, %struct.CUMULATIVE_ARGS, %struct.rtx_def*, %struct.rtx_def*, %struct.initial_value_struct*, %struct.rtx_def*, %struct.rtx_def*, %struct.rtx_def*, %struct.rtx_def*, %struct.rtx_def*, %struct.rtx_def*, i8, i32, i64, %struct.tree_node*, %struct.tree_node*, %struct.rtx_def*, %struct.VEC_temp_slot_p_gc*, %struct.temp_slot*, %struct.var_refs_queue*, i32, i32, i32, i32, %struct.machine_function*, i32, i32, %struct.language_function*, %struct.htab*, %struct.rtx_def*, i32, i32, i32, %struct.__sbuf, %struct.VEC_tree_gc*, %struct.tree_node*, i8*, i8*, i8*, i8*, i8*, %struct.tree_node*, i8, i8, i8, i8, i8, i8 }
+ %struct.htab = type { i32 (i8*)*, i32 (i8*, i8*)*, void (i8*)*, i8**, i32, i32, i32, i32, i32, i8* (i32, i32)*, void (i8*)*, i8*, i8* (i8*, i32, i32)*, void (i8*, i8*)*, i32 }
+ %struct.initial_value_struct = type opaque
+ %struct.lang_decl = type opaque
+ %struct.language_function = type opaque
+ %struct.loop = type { i32, %struct.basic_block_def*, %struct.basic_block_def*, %llvm.dbg.anchor.type, i32, i32, i32, i32, %struct.loop**, i32, %struct.loop*, %struct.loop*, %struct.loop*, %struct.loop*, i8*, %struct.tree_node*, %struct.tree_node*, %struct.nb_iter_bound*, %struct.edge_def*, i32 }
+ %struct.machine_function = type opaque
+ %struct.maydef_optype_d = type { %struct.maydef_optype_d*, %struct.tree_node*, %struct.tree_node*, %struct.ssa_use_operand_d }
+ %struct.nb_iter_bound = type { %struct.tree_node*, %struct.tree_node*, %struct.nb_iter_bound* }
+ %struct.object_block = type { %struct.section*, i32, i64, %struct.VEC_rtx_gc*, %struct.VEC_rtx_gc* }
+ %struct.obstack = type { i32, %struct._obstack_chunk*, i8*, i8*, i8*, i32, i32, %struct._obstack_chunk* (i8*, i32)*, void (i8*, %struct._obstack_chunk*)*, i8*, i8 }
+ %struct.rtl_bb_info = type { %struct.rtx_def*, %struct.rtx_def*, %struct.bitmap_head_def*, %struct.bitmap_head_def*, %struct.rtx_def*, %struct.rtx_def*, i32 }
+ %struct.rtx_def = type { i16, i8, i8, %struct.u }
+ %struct.section = type { %struct.unnamed_section }
+ %struct.sequence_stack = type { %struct.rtx_def*, %struct.rtx_def*, %struct.sequence_stack* }
+ %struct.ssa_use_operand_d = type { %struct.ssa_use_operand_d*, %struct.ssa_use_operand_d*, %struct.tree_node*, %struct.tree_node** }
+ %struct.stmt_ann_d = type { %struct.tree_ann_common_d, i8, %struct.basic_block_def*, %struct.stmt_operands_d, %struct.bitmap_head_def*, i32, i8* }
+ %struct.stmt_operands_d = type { %struct.def_optype_d*, %struct.use_optype_d*, %struct.maydef_optype_d*, %struct.vuse_optype_d*, %struct.maydef_optype_d* }
+ %struct.temp_slot = type opaque
+ %struct.tree_ann_common_d = type { i32, i8*, %struct.tree_node* }
+ %struct.tree_ann_d = type { %struct.stmt_ann_d }
+ %struct.tree_common = type { %struct.tree_node*, %struct.tree_node*, %struct.tree_ann_d*, i8, i8, i8, i8, i8 }
+ %struct.tree_decl_common = type { %struct.tree_decl_minimal, %struct.tree_node*, i8, i8, i8, i8, i8, i32, %struct.tree_decl_u1, %struct.tree_node*, %struct.tree_node*, %struct.tree_node*, %struct.tree_node*, i64, %struct.lang_decl* }
+ %struct.tree_decl_minimal = type { %struct.tree_common, %struct.__sbuf, i32, %struct.tree_node*, %struct.tree_node* }
+ %struct.tree_decl_non_common = type { %struct.tree_decl_with_vis, %struct.tree_node*, %struct.tree_node*, %struct.tree_node*, %struct.tree_node* }
+ %struct.tree_decl_u1 = type { i64 }
+ %struct.tree_decl_with_rtl = type { %struct.tree_decl_common, %struct.rtx_def*, i32 }
+ %struct.tree_decl_with_vis = type { %struct.tree_decl_with_rtl, %struct.tree_node*, %struct.tree_node*, i8, i8, i8 }
+ %struct.tree_function_decl = type { %struct.tree_decl_non_common, i8, i8, i64, %struct.function* }
+ %struct.tree_node = type { %struct.tree_function_decl }
+ %struct.u = type { %struct.block_symbol }
+ %struct.unnamed_section = type { %struct.cfg_stats_d, void (i8*)*, i8*, %struct.section* }
+ %struct.use_optype_d = type { %struct.use_optype_d*, %struct.ssa_use_operand_d }
+ %struct.var_refs_queue = type { %struct.rtx_def*, i32, i32, %struct.var_refs_queue* }
+ %struct.varasm_status = type opaque
+ %struct.vuse_optype_d = type { %struct.vuse_optype_d*, %struct.tree_node*, %struct.ssa_use_operand_d }
+ at llvm.used = appending global [1 x i8*] [ i8* bitcast (%struct.edge_def* (%struct.edge_def*, %struct.basic_block_def*)* @tree_redirect_edge_and_branch to i8*) ], section "llvm.metadata" ; <[1 x i8*]*> [#uses=0]
+
+define %struct.edge_def* @tree_redirect_edge_and_branch(%struct.edge_def* %e1, %struct.basic_block_def* %dest2) nounwind {
+entry:
+ br label %bb497
+
+bb483: ; preds = %bb497
+ %tmp496 = load %struct.tree_node** null, align 4 ; <%struct.tree_node*> [#uses=1]
+ br label %bb497
+
+bb497: ; preds = %bb483, %entry
+ %cases.0 = phi %struct.tree_node* [ %tmp496, %bb483 ], [ null, %entry ] ; <%struct.tree_node*> [#uses=1]
+ %last.0 = phi %struct.tree_node* [ %cases.0, %bb483 ], [ undef, %entry ] ; <%struct.tree_node*> [#uses=1]
+ br i1 false, label %bb483, label %bb502
+
+bb502: ; preds = %bb497
+ br i1 false, label %bb507, label %bb841
+
+bb507: ; preds = %bb502
+ %tmp517 = getelementptr %struct.tree_node* %last.0, i32 0, i32 0 ; <%struct.tree_function_decl*> [#uses=1]
+ %tmp517518 = bitcast %struct.tree_function_decl* %tmp517 to %struct.tree_common* ; <%struct.tree_common*> [#uses=1]
+ %tmp519 = getelementptr %struct.tree_common* %tmp517518, i32 0, i32 0 ; <%struct.tree_node**> [#uses=1]
+ store %struct.tree_node* null, %struct.tree_node** %tmp519, align 4
+ br label %bb841
+
+bb841: ; preds = %bb507, %bb502
+ unreachable
+}
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