1; RUN: llc < %s -march=x86 -disable-block-placement | FileCheck %s 2; 3; Test RegistersDefinedFromSameValue. We have multiple copies of the same vreg: 4; while.body85.i: 5; vreg1 = copy vreg2 6; vreg2 = add 7; critical edge from land.lhs.true.i -> if.end117.i: 8; vreg27 = vreg2 9; critical edge from land.lhs.true103.i -> if.end117.i: 10; vreg27 = vreg2 11; if.then108.i: 12; vreg27 = vreg1 13; 14; Prior to fixing PR10920 401.bzip miscompile, the coalescer would 15; consider vreg1 and vreg27 to be copies of the same value. It would 16; then remove one of the critical edge copes, which cannot safely be removed. 17 18; There are two obvious ways the register-allocator could go here, either 19; reusing the pre-addition register later, or the post-addition one. Currently, 20; it does the latter, so we check: 21 22; CHECK: # %while.body85.i{{$}} 23; CHECK-NOT: # % 24; CHECK-NOT: add 25; CHECK: movl %[[POSTR:e[abcdxi]+]], %[[PRER:e[abcdxi]+]] 26; CHECK: addl %{{.*}}, %[[POSTR]] 27; CHECK: # %while.end.i 28; CHECK-NOT: movl %[[POSTR]] 29; CHECK: # %land.lhs.true.i 30; CHECK-NOT: movl %[[POSTR]] 31; CHECK: # %land.lhs.true103.i 32; CHECK-NOT: movl %[[POSTR]] 33; CHECK: # %if.then108.i 34; CHECK: movl %[[PRER]], %[[POSTR]] 35; CHECK: # %if.end117.i 36; and use it for fprintf: 37; CHECK: movl %[[POSTR]], 12(%esp) 38 39 40; If it ever reverts to reusing the pre-addition register then we should 41; *probably* check this instead (it certainly worked last time): 42 43; CHECKALT: # %while.body85.i 44; CHECKALT-NOT: # % 45; CHECKALT-NOT: add 46; CHECKALT: movl %[[POSTR:e[abcdxi]+]], %[[PRER:e[abcdxi]+]] 47; CHECKALT: addl %{{.*}}, %[[POSTR]] 48; CHECKALT: # %while.end.i 49; CHECKALT: movl %[[POSTR]], %[[USER:e[abcdxi]+]] 50; CHECKALT: # %land.lhs.true.i 51; CHECKALT: movl %[[POSTR]], %[[USER]] 52; CHECKALT: # %land.lhs.true103.i 53; CHECKALT: movl %[[POSTR]], %[[USER]] 54; CHECKALT: # %if.then108.i 55; [[PRER] live out, so nothing on this path should define it. 56; CHECKALT-NOT: , %[[PRER]] 57; CHECKALT: # %if.end117.i 58 59target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128-n8:16:32" 60 61@.str3 = external unnamed_addr constant [59 x i8], align 1 62 63define void @BZ2_compressBlock() nounwind ssp { 64entry: 65 br i1 undef, label %if.then68, label %if.end85 66 67if.then68: ; preds = %entry 68 br label %for.body.i.i 69 70for.body.i.i: ; preds = %for.inc.i.i, %if.then68 71 br i1 undef, label %for.inc.i.i, label %if.then.i.i 72 73if.then.i.i: ; preds = %for.body.i.i 74 br label %for.inc.i.i 75 76for.inc.i.i: ; preds = %if.then.i.i, %for.body.i.i 77 br i1 undef, label %makeMaps_e.exit.i, label %for.body.i.i 78 79makeMaps_e.exit.i: ; preds = %for.inc.i.i 80 br i1 undef, label %for.cond19.preheader.i, label %for.cond.for.cond19.preheader_crit_edge.i 81 82for.cond.for.cond19.preheader_crit_edge.i: ; preds = %makeMaps_e.exit.i 83 unreachable 84 85for.cond19.preheader.i: ; preds = %makeMaps_e.exit.i 86 br i1 undef, label %for.body25.lr.ph.i, label %for.cond33.preheader.i 87 88for.body25.lr.ph.i: ; preds = %for.cond19.preheader.i 89 br label %for.body25.i 90 91for.cond33.preheader.i: ; preds = %for.body25.i, %for.cond19.preheader.i 92 br i1 undef, label %if.then.i, label %if.end.i 93 94for.body25.i: ; preds = %for.body25.i, %for.body25.lr.ph.i 95 br i1 undef, label %for.body25.i, label %for.cond33.preheader.i 96 97if.then.i: ; preds = %for.cond33.preheader.i 98 br label %if.end.i 99 100if.end.i: ; preds = %if.then.i, %for.cond33.preheader.i 101 br i1 undef, label %for.inc27.us.5.i, label %for.end30.i 102 103for.end30.i: ; preds = %for.inc27.us.5.i, %if.end.i 104 br i1 undef, label %if.end36.i, label %if.then35.i 105 106if.then35.i: ; preds = %for.end30.i 107 unreachable 108 109if.end36.i: ; preds = %for.end30.i 110 %sub83.i = add nsw i32 undef, 1 111 br label %while.body.i188 112 113for.cond182.preheader.i: ; preds = %for.end173.i 114 br i1 undef, label %for.inc220.us.i, label %while.body300.preheader.i 115 116while.body.i188: ; preds = %for.end173.i, %if.end36.i 117 %gs.0526.i = phi i32 [ 0, %if.end36.i ], [ %add177.i, %for.end173.i ] 118 %or.cond514517.i = and i1 false, undef 119 br i1 %or.cond514517.i, label %while.body85.i, label %if.end117.i 120 121while.body85.i: ; preds = %while.body85.i, %while.body.i188 122 %aFreq.0518.i = phi i32 [ %add93.i, %while.body85.i ], [ 0, %while.body.i188 ] 123 %inc87.i = add nsw i32 0, 1 124 %tmp91.i = load i32, i32* undef, align 4 125 %add93.i = add nsw i32 %tmp91.i, %aFreq.0518.i 126 %or.cond514.i = and i1 undef, false 127 br i1 %or.cond514.i, label %while.body85.i, label %while.end.i 128 129while.end.i: ; preds = %while.body85.i 130 br i1 undef, label %land.lhs.true.i, label %if.end117.i 131 132land.lhs.true.i: ; preds = %while.end.i 133 br i1 undef, label %land.lhs.true103.i, label %if.end117.i 134 135land.lhs.true103.i: ; preds = %land.lhs.true.i 136 br i1 undef, label %if.then108.i, label %if.end117.i 137 138if.then108.i: ; preds = %land.lhs.true103.i 139 br label %if.end117.i 140 141if.end117.i: ; preds = %if.then108.i, %land.lhs.true103.i, %land.lhs.true.i, %while.end.i, %while.body.i188 142 %aFreq.1.i = phi i32 [ %aFreq.0518.i, %if.then108.i ], [ %add93.i, %land.lhs.true103.i ], [ %add93.i, %land.lhs.true.i ], [ %add93.i, %while.end.i ], [ 0, %while.body.i188 ] 143 %ge.1.i = phi i32 [ 0, %if.then108.i ], [ %inc87.i, %land.lhs.true103.i ], [ %inc87.i, %land.lhs.true.i ], [ %inc87.i, %while.end.i ], [ 0, %while.body.i188 ] 144 br i1 undef, label %if.then122.i, label %for.cond138.preheader.i 145 146if.then122.i: ; preds = %if.end117.i 147 call void (...) @fprintf(i32 undef, i32 %gs.0526.i, i32 %ge.1.i, i32 %aFreq.1.i, double undef) nounwind 148 br label %for.cond138.preheader.i 149 150for.cond138.preheader.i: ; preds = %if.then122.i, %if.end117.i 151 br i1 undef, label %for.body143.lr.ph.i, label %for.end173.i 152 153for.body143.lr.ph.i: ; preds = %for.cond138.preheader.i 154 br label %for.body143.i 155 156for.body143.i: ; preds = %for.body143.i, %for.body143.lr.ph.i 157 br i1 undef, label %for.end173.i, label %for.body143.i 158 159for.end173.i: ; preds = %for.body143.i, %for.cond138.preheader.i 160 %add177.i = add nsw i32 %ge.1.i, 1 161 %cmp73.i = icmp sgt i32 undef, 0 162 br i1 %cmp73.i, label %while.body.i188, label %for.cond182.preheader.i 163 164for.inc220.us.i: ; preds = %for.cond182.preheader.i 165 unreachable 166 167while.body300.preheader.i: ; preds = %for.cond182.preheader.i 168 br i1 undef, label %for.end335.i, label %while.end2742.i 169 170for.end335.i: ; preds = %for.end2039.i, %while.body300.preheader.i 171 br label %for.body2021.i 172 173for.body2021.i: ; preds = %for.body2021.i, %for.end335.i 174 br i1 undef, label %for.body2021.i, label %for.end2039.i 175 176for.end2039.i: ; preds = %for.body2021.i 177 br label %for.end335.i 178 179while.end2742.i: ; preds = %while.body300.preheader.i 180 br i1 undef, label %if.then2748.i, label %for.body2778.i 181 182if.then2748.i: ; preds = %while.end2742.i 183 unreachable 184 185for.body2778.i: ; preds = %while.end2742.i 186 unreachable 187 188for.inc27.us.5.i: ; preds = %if.end.i 189 br label %for.end30.i 190 191if.end85: ; preds = %entry 192 ret void 193} 194 195declare void @fprintf(...) nounwind 196