Files
clang-p2996/llvm/test/Transforms/GCOVProfiling/function-numbering.ll
Chandler Carruth 71c3a3fac5 [GCOV] Emit the writeout function as nested loops of global data.
Summary:
Prior to this change, LLVM would in some cases emit *massive* writeout
functions with many 10s of 1000s of function calls in straight-line
code. This is a very wasteful way to represent what are fundamentally
loops and creates a number of scalability issues. Among other things,
register allocating these calls is extremely expensive. While D46127 makes this
less severe, we'll still run into scaling issues with this eventually. If not
in the compile time, just from the code size.

Now the pass builds up global data structures modeling the inputs to
these functions, and simply loops over the data structures calling the
relevant functions with those values. This ensures that the code size is
a fixed and only data size grows with larger amounts of coverage data.

A trivial change to IRBuilder is included to make it easier to build
the constants that make up the global data.

Reviewers: wmi, echristo

Subscribers: sanjoy, mcrosier, llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D46357

llvm-svn: 331407
2018-05-02 22:24:39 +00:00

124 lines
7.6 KiB
LLVM

; Test that GCOV instrumentation numbers functions correctly when some
; functions aren't emitted.
; Inject metadata to set the .gcno file location
; RUN: rm -rf %t && mkdir -p %t
; RUN: echo '!14 = !{!"%/t/function-numbering.ll", !0}' > %t/1
; RUN: cat %s %t/1 > %t/2
; RUN: opt -insert-gcov-profiling -S < %t/2 | FileCheck --check-prefix GCDA %s
; RUN: llvm-cov gcov -n -dump %t/function-numbering.gcno 2>&1 | FileCheck --check-prefix GCNO %s
; RUNN: rm %t/function-numbering.gcno
; RUN: opt -passes=insert-gcov-profiling -S < %t/2 | FileCheck --check-prefix GCDA %s
; RUN: llvm-cov gcov -n -dump %t/function-numbering.gcno 2>&1 | FileCheck --check-prefix GCNO %s
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx10.10.0"
; GCDA: @[[FOO:[0-9]+]] = private unnamed_addr constant [4 x i8] c"foo\00"
; GCDA-NOT: @{{[0-9]+}} = private unnamed_addr constant .* c"bar\00"
; GCDA: @[[BAZ:[0-9]+]] = private unnamed_addr constant [4 x i8] c"baz\00"
; GCDA: @__llvm_internal_gcov_emit_function_args.0 = internal unnamed_addr constant
; GCDA-SAME: { i32 0, i8* getelementptr inbounds ([4 x i8], [4 x i8]* @[[FOO]]
; GCDA-SAME: { i32 1, i8* getelementptr inbounds ([4 x i8], [4 x i8]* @[[BAZ]]
;
; GCDA-LABEL: define internal void @__llvm_gcov_writeout() {{.*}} {
; GCDA-NEXT: entry:
; GCDA-NEXT: br label %[[FILE_LOOP_HEADER:.*]]
;
; GCDA: [[FILE_LOOP_HEADER]]:
; GCDA-NEXT: %[[IV:.*]] = phi i32 [ 0, %entry ], [ %[[NEXT_IV:.*]], %[[FILE_LOOP_LATCH:.*]] ]
; GCDA-NEXT: %[[FILE_INFO:.*]] = getelementptr inbounds {{.*}}, {{.*}}* @__llvm_internal_gcov_emit_file_info, i32 0, i32 %[[IV]]
; GCDA-NEXT: %[[START_FILE_ARGS:.*]] = getelementptr inbounds {{.*}}, {{.*}}* %[[FILE_INFO]], i32 0, i32 0
; GCDA-NEXT: %[[START_FILE_ARG_0_PTR:.*]] = getelementptr inbounds {{.*}}, {{.*}}* %[[START_FILE_ARGS]], i32 0, i32 0
; GCDA-NEXT: %[[START_FILE_ARG_0:.*]] = load i8*, i8** %[[START_FILE_ARG_0_PTR]]
; GCDA-NEXT: %[[START_FILE_ARG_1_PTR:.*]] = getelementptr inbounds {{.*}}, {{.*}}* %[[START_FILE_ARGS]], i32 0, i32 1
; GCDA-NEXT: %[[START_FILE_ARG_1:.*]] = load i8*, i8** %[[START_FILE_ARG_1_PTR]]
; GCDA-NEXT: %[[START_FILE_ARG_2_PTR:.*]] = getelementptr inbounds {{.*}}, {{.*}}* %[[START_FILE_ARGS]], i32 0, i32 2
; GCDA-NEXT: %[[START_FILE_ARG_2:.*]] = load i32, i32* %[[START_FILE_ARG_2_PTR]]
; GCDA-NEXT: call void @llvm_gcda_start_file(i8* %[[START_FILE_ARG_0]], i8* %[[START_FILE_ARG_1]], i32 %[[START_FILE_ARG_2]])
; GCDA-NEXT: %[[NUM_COUNTERS_PTR:.*]] = getelementptr inbounds {{.*}}, {{.*}}* %[[FILE_INFO]], i32 0, i32 1
; GCDA-NEXT: %[[NUM_COUNTERS:.*]] = load i32, i32* %[[NUM_COUNTERS_PTR]]
; GCDA-NEXT: %[[EMIT_FUN_ARGS_ARRAY_PTR:.*]] = getelementptr inbounds {{.*}}, {{.*}}* %[[FILE_INFO]], i32 0, i32 2
; GCDA-NEXT: %[[EMIT_FUN_ARGS_ARRAY:.*]] = load {{.*}}*, {{.*}}** %[[EMIT_FUN_ARGS_ARRAY_PTR]]
; GCDA-NEXT: %[[EMIT_ARCS_ARGS_ARRAY_PTR:.*]] = getelementptr inbounds {{.*}}, {{.*}}* %[[FILE_INFO]], i32 0, i32 3
; GCDA-NEXT: %[[EMIT_ARCS_ARGS_ARRAY:.*]] = load {{.*}}*, {{.*}}** %[[EMIT_ARCS_ARGS_ARRAY_PTR]]
; GCDA-NEXT: %[[ENTER_COUNTER_LOOP_COND:.*]] = icmp slt i32 0, %[[NUM_COUNTERS]]
; GCDA-NEXT: br i1 %[[ENTER_COUNTER_LOOP_COND]], label %[[COUNTER_LOOP:.*]], label %[[FILE_LOOP_LATCH]]
;
; GCDA: [[COUNTER_LOOP]]:
; GCDA-NEXT: %[[JV:.*]] = phi i32 [ 0, %[[FILE_LOOP_HEADER]] ], [ %[[NEXT_JV:.*]], %[[COUNTER_LOOP]] ]
; GCDA-NEXT: %[[EMIT_FUN_ARGS:.*]] = getelementptr inbounds {{.*}}, {{.*}}* %[[EMIT_FUN_ARGS_ARRAY]], i32 %[[JV]]
; GCDA-NEXT: %[[EMIT_FUN_ARG_0_PTR:.*]] = getelementptr inbounds {{.*}}, {{.*}}* %[[EMIT_FUN_ARGS]], i32 0, i32 0
; GCDA-NEXT: %[[EMIT_FUN_ARG_0:.*]] = load i32, i32* %[[EMIT_FUN_ARG_0_PTR]]
; GCDA-NEXT: %[[EMIT_FUN_ARG_1_PTR:.*]] = getelementptr inbounds {{.*}}, {{.*}}* %[[EMIT_FUN_ARGS]], i32 0, i32 1
; GCDA-NEXT: %[[EMIT_FUN_ARG_1:.*]] = load i8*, i8** %[[EMIT_FUN_ARG_1_PTR]]
; GCDA-NEXT: %[[EMIT_FUN_ARG_2_PTR:.*]] = getelementptr inbounds {{.*}}, {{.*}}* %[[EMIT_FUN_ARGS]], i32 0, i32 2
; GCDA-NEXT: %[[EMIT_FUN_ARG_2:.*]] = load i32, i32* %[[EMIT_FUN_ARG_2_PTR]]
; GCDA-NEXT: %[[EMIT_FUN_ARG_3_PTR:.*]] = getelementptr inbounds {{.*}}, {{.*}}* %[[EMIT_FUN_ARGS]], i32 0, i32 3
; GCDA-NEXT: %[[EMIT_FUN_ARG_3:.*]] = load i8, i8* %[[EMIT_FUN_ARG_3_PTR]]
; GCDA-NEXT: %[[EMIT_FUN_ARG_4_PTR:.*]] = getelementptr inbounds {{.*}}, {{.*}}* %[[EMIT_FUN_ARGS]], i32 0, i32 4
; GCDA-NEXT: %[[EMIT_FUN_ARG_4:.*]] = load i32, i32* %[[EMIT_FUN_ARG_4_PTR]]
; GCDA-NEXT: call void @llvm_gcda_emit_function(i32 %[[EMIT_FUN_ARG_0]],
; GCDA-SAME: i8* %[[EMIT_FUN_ARG_1]],
; GCDA-SAME: i32 %[[EMIT_FUN_ARG_2]],
; GCDA-SAME: i8 %[[EMIT_FUN_ARG_3]],
; GCDA-SAME: i32 %[[EMIT_FUN_ARG_4]])
; GCDA-NEXT: %[[EMIT_ARCS_ARGS:.*]] = getelementptr inbounds {{.*}}, {{.*}}* %[[EMIT_ARCS_ARGS_ARRAY]], i32 %[[JV]]
; GCDA-NEXT: %[[EMIT_ARCS_ARG_0_PTR:.*]] = getelementptr inbounds {{.*}}, {{.*}}* %[[EMIT_ARCS_ARGS]], i32 0, i32 0
; GCDA-NEXT: %[[EMIT_ARCS_ARG_0:.*]] = load i32, i32* %[[EMIT_ARCS_ARG_0_PTR]]
; GCDA-NEXT: %[[EMIT_ARCS_ARG_1_PTR:.*]] = getelementptr inbounds {{.*}}, {{.*}}* %[[EMIT_ARCS_ARGS]], i32 0, i32 1
; GCDA-NEXT: %[[EMIT_ARCS_ARG_1:.*]] = load i64*, i64** %[[EMIT_ARCS_ARG_1_PTR]]
; GCDA-NEXT: call void @llvm_gcda_emit_arcs(i32 %[[EMIT_ARCS_ARG_0]],
; GCDA-SAME: i64* %[[EMIT_ARCS_ARG_1]])
; GCDA-NEXT: %[[NEXT_JV]] = add i32 %[[JV]], 1
; GCDA-NEXT: %[[COUNTER_LOOP_COND:.*]] = icmp slt i32 %[[NEXT_JV]], %[[NUM_COUNTERS]]
; GCDA-NEXT: br i1 %[[COUNTER_LOOP_COND]], label %[[COUNTER_LOOP]], label %[[FILE_LOOP_LATCH]]
;
; GCDA: [[FILE_LOOP_LATCH]]:
; GCDA-NEXT: call void @llvm_gcda_summary_info()
; GCDA-NEXT: call void @llvm_gcda_end_file()
; GCDA-NEXT: %[[NEXT_IV]] = add i32 %[[IV]], 1
; GCDA-NEXT: %[[FILE_LOOP_COND:.*]] = icmp slt i32 %[[NEXT_IV]], 1
; GCDA-NEXT: br i1 %[[FILE_LOOP_COND]], label %[[FILE_LOOP_HEADER]], label %[[EXIT:.*]]
;
; GCDA: [[EXIT]]:
; GCDA-NEXT: ret void
; GCNO: == foo (0) @
; GCNO-NOT: == bar ({{[0-9]+}}) @
; GCNO: == baz (1) @
define void @foo() !dbg !4 {
ret void, !dbg !12
}
define void @bar() !dbg !7 {
; This function is referenced by the debug info, but no lines have locations.
ret void
}
define void @baz() !dbg !8 {
ret void, !dbg !13
}
!llvm.gcov = !{!14}
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!9, !10}
!llvm.ident = !{!11}
!0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.6.0 ", isOptimized: false, emissionKind: LineTablesOnly, file: !1, enums: !2, retainedTypes: !2, globals: !2, imports: !2)
!1 = !DIFile(filename: ".../llvm/test/Transforms/GCOVProfiling/function-numbering.ll", directory: "")
!2 = !{}
!4 = distinct !DISubprogram(name: "foo", line: 1, isLocal: false, isDefinition: true, isOptimized: false, unit: !0, scopeLine: 1, file: !1, scope: !5, type: !6, variables: !2)
!5 = !DIFile(filename: ".../llvm/test/Transforms/GCOVProfiling/function-numbering.ll", directory: "")
!6 = !DISubroutineType(types: !2)
!7 = distinct !DISubprogram(name: "bar", line: 2, isLocal: false, isDefinition: true, isOptimized: false, unit: !0, scopeLine: 2, file: !1, scope: !5, type: !6, variables: !2)
!8 = distinct !DISubprogram(name: "baz", line: 3, isLocal: false, isDefinition: true, isOptimized: false, unit: !0, scopeLine: 3, file: !1, scope: !5, type: !6, variables: !2)
!9 = !{i32 2, !"Dwarf Version", i32 2}
!10 = !{i32 2, !"Debug Info Version", i32 3}
!11 = !{!"clang version 3.6.0 "}
!12 = !DILocation(line: 1, column: 13, scope: !4)
!13 = !DILocation(line: 3, column: 13, scope: !8)