| ; RUN: opt < %s -analyze -block-freq -enable-new-pm=0 | FileCheck %s |
| ; RUN: opt < %s -passes='print<block-freq>' -disable-output 2>&1 | FileCheck %s |
| |
| ; This code contains three loops. One is triple-nested, the |
| ; second is double nested and the third is a single loop. At |
| ; runtime, all three loops execute 1,000,000 times each. We use to |
| ; give different frequencies to each of the loops because loop |
| ; scales were limited to no more than 4,096. |
| ; |
| ; This was penalizing the hotness of the second and third loops |
| ; because BFI was reducing the loop scale for for.cond16 and |
| ; for.cond26 to a max of 4,096. |
| ; |
| ; Without this restriction, all loops are now correctly given the same |
| ; frequency values. |
| ; |
| ; Original C code: |
| ; |
| ; |
| ; int g; |
| ; __attribute__((noinline)) void bar() { |
| ; g++; |
| ; } |
| ; |
| ; extern int printf(const char*, ...); |
| ; |
| ; int main() |
| ; { |
| ; int i, j, k; |
| ; |
| ; g = 0; |
| ; for (i = 0; i < 100; i++) |
| ; for (j = 0; j < 100; j++) |
| ; for (k = 0; k < 100; k++) |
| ; bar(); |
| ; |
| ; printf ("g = %d\n", g); |
| ; g = 0; |
| ; |
| ; for (i = 0; i < 100; i++) |
| ; for (j = 0; j < 10000; j++) |
| ; bar(); |
| ; |
| ; printf ("g = %d\n", g); |
| ; g = 0; |
| ; |
| ; |
| ; for (i = 0; i < 1000000; i++) |
| ; bar(); |
| ; |
| ; printf ("g = %d\n", g); |
| ; g = 0; |
| ; } |
| |
| @g = common global i32 0, align 4 |
| @.str = private unnamed_addr constant [8 x i8] c"g = %d\0A\00", align 1 |
| |
| declare void @bar() |
| declare i32 @printf(i8*, ...) |
| |
| ; CHECK: Printing analysis {{.*}} for function 'main': |
| ; CHECK-NEXT: block-frequency-info: main |
| define i32 @main() { |
| entry: |
| %retval = alloca i32, align 4 |
| %i = alloca i32, align 4 |
| %j = alloca i32, align 4 |
| %k = alloca i32, align 4 |
| store i32 0, i32* %retval |
| store i32 0, i32* @g, align 4 |
| store i32 0, i32* %i, align 4 |
| br label %for.cond |
| |
| for.cond: ; preds = %for.inc10, %entry |
| %0 = load i32, i32* %i, align 4 |
| %cmp = icmp slt i32 %0, 100 |
| br i1 %cmp, label %for.body, label %for.end12, !prof !1 |
| |
| for.body: ; preds = %for.cond |
| store i32 0, i32* %j, align 4 |
| br label %for.cond1 |
| |
| for.cond1: ; preds = %for.inc7, %for.body |
| %1 = load i32, i32* %j, align 4 |
| %cmp2 = icmp slt i32 %1, 100 |
| br i1 %cmp2, label %for.body3, label %for.end9, !prof !2 |
| |
| for.body3: ; preds = %for.cond1 |
| store i32 0, i32* %k, align 4 |
| br label %for.cond4 |
| |
| for.cond4: ; preds = %for.inc, %for.body3 |
| %2 = load i32, i32* %k, align 4 |
| %cmp5 = icmp slt i32 %2, 100 |
| br i1 %cmp5, label %for.body6, label %for.end, !prof !3 |
| |
| ; CHECK: - for.body6: float = 500000.5, int = 4000004 |
| for.body6: ; preds = %for.cond4 |
| call void @bar() |
| br label %for.inc |
| |
| for.inc: ; preds = %for.body6 |
| %3 = load i32, i32* %k, align 4 |
| %inc = add nsw i32 %3, 1 |
| store i32 %inc, i32* %k, align 4 |
| br label %for.cond4 |
| |
| for.end: ; preds = %for.cond4 |
| br label %for.inc7 |
| |
| for.inc7: ; preds = %for.end |
| %4 = load i32, i32* %j, align 4 |
| %inc8 = add nsw i32 %4, 1 |
| store i32 %inc8, i32* %j, align 4 |
| br label %for.cond1 |
| |
| for.end9: ; preds = %for.cond1 |
| br label %for.inc10 |
| |
| for.inc10: ; preds = %for.end9 |
| %5 = load i32, i32* %i, align 4 |
| %inc11 = add nsw i32 %5, 1 |
| store i32 %inc11, i32* %i, align 4 |
| br label %for.cond |
| |
| for.end12: ; preds = %for.cond |
| %6 = load i32, i32* @g, align 4 |
| %call = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([8 x i8], [8 x i8]* @.str, i32 0, i32 0), i32 %6) |
| store i32 0, i32* @g, align 4 |
| store i32 0, i32* %i, align 4 |
| br label %for.cond13 |
| |
| for.cond13: ; preds = %for.inc22, %for.end12 |
| %7 = load i32, i32* %i, align 4 |
| %cmp14 = icmp slt i32 %7, 100 |
| br i1 %cmp14, label %for.body15, label %for.end24, !prof !1 |
| |
| for.body15: ; preds = %for.cond13 |
| store i32 0, i32* %j, align 4 |
| br label %for.cond16 |
| |
| for.cond16: ; preds = %for.inc19, %for.body15 |
| %8 = load i32, i32* %j, align 4 |
| %cmp17 = icmp slt i32 %8, 10000 |
| br i1 %cmp17, label %for.body18, label %for.end21, !prof !4 |
| |
| ; CHECK: - for.body18: float = 499999.9, int = 3999998 |
| for.body18: ; preds = %for.cond16 |
| call void @bar() |
| br label %for.inc19 |
| |
| for.inc19: ; preds = %for.body18 |
| %9 = load i32, i32* %j, align 4 |
| %inc20 = add nsw i32 %9, 1 |
| store i32 %inc20, i32* %j, align 4 |
| br label %for.cond16 |
| |
| for.end21: ; preds = %for.cond16 |
| br label %for.inc22 |
| |
| for.inc22: ; preds = %for.end21 |
| %10 = load i32, i32* %i, align 4 |
| %inc23 = add nsw i32 %10, 1 |
| store i32 %inc23, i32* %i, align 4 |
| br label %for.cond13 |
| |
| for.end24: ; preds = %for.cond13 |
| %11 = load i32, i32* @g, align 4 |
| %call25 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([8 x i8], [8 x i8]* @.str, i32 0, i32 0), i32 %11) |
| store i32 0, i32* @g, align 4 |
| store i32 0, i32* %i, align 4 |
| br label %for.cond26 |
| |
| for.cond26: ; preds = %for.inc29, %for.end24 |
| %12 = load i32, i32* %i, align 4 |
| %cmp27 = icmp slt i32 %12, 1000000 |
| br i1 %cmp27, label %for.body28, label %for.end31, !prof !5 |
| |
| ; CHECK: - for.body28: float = 499995.2, int = 3999961 |
| for.body28: ; preds = %for.cond26 |
| call void @bar() |
| br label %for.inc29 |
| |
| for.inc29: ; preds = %for.body28 |
| %13 = load i32, i32* %i, align 4 |
| %inc30 = add nsw i32 %13, 1 |
| store i32 %inc30, i32* %i, align 4 |
| br label %for.cond26 |
| |
| for.end31: ; preds = %for.cond26 |
| %14 = load i32, i32* @g, align 4 |
| %call32 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([8 x i8], [8 x i8]* @.str, i32 0, i32 0), i32 %14) |
| store i32 0, i32* @g, align 4 |
| %15 = load i32, i32* %retval |
| ret i32 %15 |
| } |
| |
| !llvm.ident = !{!0} |
| |
| !0 = !{!"clang version 3.7.0 (trunk 232635) (llvm/trunk 232636)"} |
| !1 = !{!"branch_weights", i32 101, i32 2} |
| !2 = !{!"branch_weights", i32 10001, i32 101} |
| !3 = !{!"branch_weights", i32 1000001, i32 10001} |
| !4 = !{!"branch_weights", i32 1000001, i32 101} |
| !5 = !{!"branch_weights", i32 1000001, i32 2} |
