1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py 2; RUN: opt -passes=simplifycfg -simplifycfg-require-and-preserve-domtree=1 -hoist-common-insts=1 -S < %s | FileCheck %s --check-prefix=HOIST 3; RUN: opt -passes=simplifycfg -simplifycfg-require-and-preserve-domtree=1 -hoist-common-insts=0 -S < %s | FileCheck %s --check-prefix=NOHOIST 4; RUN: opt -passes=simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S < %s | FileCheck %s --check-prefix=NOHOIST 5 6; This example is produced from a very basic C code: 7; 8; void f0(); 9; void f1(); 10; void f2(); 11; 12; void loop(int width) { 13; if(width < 1) 14; return; 15; for(int i = 0; i < width - 1;+i) { 16; f0(); 17; f1(); 18; } 19; f0(); 20; f2(); 21; } 22 23; We have a choice here. We can either 24; * hoist the f0() call into loop header, 25; * which potentially makes loop rotation unprofitable since loop header might 26; have grown above certain threshold, and such unrotated loops will be 27; ignored by LoopVectorizer, preventing vectorization 28; * or loop rotation will succeed, resulting in some weird PHIs that will also 29; harm vectorization 30; * or not hoist f0() call before performing loop rotation, 31; at the cost of potential code bloat and/or potentially successfully rotating 32; the loops, vectorizing them at the cost of compile time. 33 34target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128" 35 36declare i1 @gen1() 37 38declare void @f0() 39declare void @f1() 40declare void @f2() 41 42declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) 43declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) 44 45define void @_Z4loopi(i1 %cmp) { 46; HOIST-LABEL: @_Z4loopi( 47; HOIST-NEXT: entry: 48; HOIST-NEXT: br i1 [[CMP:%.*]], label [[RETURN:%.*]], label [[FOR_COND:%.*]] 49; HOIST: for.cond: 50; HOIST-NEXT: [[CMP1:%.*]] = call i1 @gen1() 51; HOIST-NEXT: call void @f0() 52; HOIST-NEXT: br i1 [[CMP1]], label [[FOR_BODY:%.*]], label [[FOR_END:%.*]] 53; HOIST: for.body: 54; HOIST-NEXT: call void @f1() 55; HOIST-NEXT: br label [[FOR_COND]] 56; HOIST: for.end: 57; HOIST-NEXT: call void @f2() 58; HOIST-NEXT: br label [[RETURN]] 59; HOIST: return: 60; HOIST-NEXT: ret void 61; 62; NOHOIST-LABEL: @_Z4loopi( 63; NOHOIST-NEXT: entry: 64; NOHOIST-NEXT: br i1 [[CMP:%.*]], label [[RETURN:%.*]], label [[FOR_COND:%.*]] 65; NOHOIST: for.cond: 66; NOHOIST-NEXT: [[CMP1:%.*]] = call i1 @gen1() 67; NOHOIST-NEXT: br i1 [[CMP1]], label [[FOR_BODY:%.*]], label [[FOR_END:%.*]] 68; NOHOIST: for.body: 69; NOHOIST-NEXT: call void @f0() 70; NOHOIST-NEXT: call void @f1() 71; NOHOIST-NEXT: br label [[FOR_COND]] 72; NOHOIST: for.end: 73; NOHOIST-NEXT: call void @f0() 74; NOHOIST-NEXT: call void @f2() 75; NOHOIST-NEXT: br label [[RETURN]] 76; NOHOIST: return: 77; NOHOIST-NEXT: ret void 78; 79entry: 80 br i1 %cmp, label %if.then, label %if.end 81 82if.then: 83 br label %return 84 85if.end: 86 br label %for.cond 87 88for.cond: 89 %cmp1 = call i1 @gen1() 90 br i1 %cmp1, label %for.body, label %for.cond.cleanup 91 92for.cond.cleanup: 93 br label %for.end 94 95for.body: 96 call void @f0() 97 call void @f1() 98 br label %for.inc 99 100for.inc: 101 br label %for.cond 102 103for.end: 104 call void @f0() 105 call void @f2() 106 br label %return 107 108return: 109 ret void 110} 111 112; A example where only the branch instructions from %if.then2 and %if.end3 need 113; to be hoisted, which effectively replaces the original branch in %if.end and 114; only requires selects for PHIs in the successor. 115define float @clamp_float_value(float %value, float %minimum_value, float %maximum_value) { 116; HOIST-LABEL: @clamp_float_value( 117; HOIST-NEXT: entry: 118; HOIST-NEXT: [[CMP:%.*]] = fcmp ogt float [[VALUE:%.*]], [[MAXIMUM_VALUE:%.*]] 119; HOIST-NEXT: [[CMP1:%.*]] = fcmp olt float [[VALUE]], [[MINIMUM_VALUE:%.*]] 120; HOIST-NEXT: [[MINIMUM_VALUE_VALUE:%.*]] = select i1 [[CMP1]], float [[MINIMUM_VALUE]], float [[VALUE]] 121; HOIST-NEXT: [[RETVAL_0:%.*]] = select i1 [[CMP]], float [[MAXIMUM_VALUE]], float [[MINIMUM_VALUE_VALUE]] 122; HOIST-NEXT: ret float [[RETVAL_0]] 123; 124; NOHOIST-LABEL: @clamp_float_value( 125; NOHOIST-NEXT: entry: 126; NOHOIST-NEXT: [[CMP:%.*]] = fcmp ogt float [[VALUE:%.*]], [[MAXIMUM_VALUE:%.*]] 127; NOHOIST-NEXT: [[CMP1:%.*]] = fcmp olt float [[VALUE]], [[MINIMUM_VALUE:%.*]] 128; NOHOIST-NEXT: [[MINIMUM_VALUE_VALUE:%.*]] = select i1 [[CMP1]], float [[MINIMUM_VALUE]], float [[VALUE]] 129; NOHOIST-NEXT: [[RETVAL_0:%.*]] = select i1 [[CMP]], float [[MAXIMUM_VALUE]], float [[MINIMUM_VALUE_VALUE]] 130; NOHOIST-NEXT: ret float [[RETVAL_0]] 131; 132entry: 133 %cmp = fcmp ogt float %value, %maximum_value 134 br i1 %cmp, label %if.then, label %if.end 135 136if.then: ; preds = %entry 137 br label %return 138 139if.end: ; preds = %entry 140 %cmp1 = fcmp olt float %value, %minimum_value 141 br i1 %cmp1, label %if.then2, label %if.end3 142 143if.then2: ; preds = %if.end 144 br label %return 145 146if.end3: ; preds = %if.end 147 br label %return 148 149return: ; preds = %if.end3, %if.then2, %if.then 150 %retval.0 = phi float [ %maximum_value, %if.then ], [ %minimum_value, %if.then2 ], [ %value, %if.end3 ] 151 ret float %retval.0 152} 153