mirror of
https://github.com/carbon-language/carbon-lang.git
synced 2026-09-28 06:40:11 +01:00
Richard Smith
c04d62a7d1
Non-entry-block allocas will allocate new stack memory each time they're reached, resulting in leaking stack memory over time for allocas in a loop. Move all such allocas to the entry block instead, and use an LLVM intrinsic to mark when the lifetime of the variable actually begins.
65 lines
3.6 KiB
Plaintext
65 lines
3.6 KiB
Plaintext
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
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// Exceptions. See /LICENSE for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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// AUTOUPDATE
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// TIP: To test this file alone, run:
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// TIP: bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/lower/testdata/operators/assignment.carbon
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// TIP: To dump output, run:
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// TIP: bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/lower/testdata/operators/assignment.carbon
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fn Main() {
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var a: i32 = 12;
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a = 9;
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var b: (i32, i32);
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b = (1, 2);
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}
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// CHECK:STDOUT: ; ModuleID = 'assignment.carbon'
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// CHECK:STDOUT: source_filename = "assignment.carbon"
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// CHECK:STDOUT:
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// CHECK:STDOUT: @tuple.loc15_5 = internal constant { i32, i32 } { i32 1, i32 2 }
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// CHECK:STDOUT:
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// CHECK:STDOUT: define void @_CMain.Main() !dbg !4 {
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// CHECK:STDOUT: entry:
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// CHECK:STDOUT: %a.var = alloca i32, align 4, !dbg !7
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// CHECK:STDOUT: %b.var = alloca { i32, i32 }, align 8, !dbg !7
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// CHECK:STDOUT: call void @llvm.lifetime.start.p0(i64 4, ptr %a.var), !dbg !7
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// CHECK:STDOUT: store i32 12, ptr %a.var, align 4, !dbg !8
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// CHECK:STDOUT: store i32 9, ptr %a.var, align 4, !dbg !9
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// CHECK:STDOUT: call void @llvm.lifetime.start.p0(i64 8, ptr %b.var), !dbg !7
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// CHECK:STDOUT: %tuple.elem0.tuple.elem = getelementptr inbounds nuw { i32, i32 }, ptr %b.var, i32 0, i32 0, !dbg !10
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// CHECK:STDOUT: %tuple.elem1.tuple.elem = getelementptr inbounds nuw { i32, i32 }, ptr %b.var, i32 0, i32 1, !dbg !10
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// CHECK:STDOUT: call void @llvm.memcpy.p0.p0.i64(ptr align 4 %b.var, ptr align 4 @tuple.loc15_5, i64 8, i1 false), !dbg !11
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// CHECK:STDOUT: ret void, !dbg !12
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// CHECK:STDOUT: }
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// CHECK:STDOUT:
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// CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
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// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #0
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// CHECK:STDOUT:
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// CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
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// CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias nocapture writeonly, ptr noalias nocapture readonly, i64, i1 immarg) #1
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// CHECK:STDOUT:
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// CHECK:STDOUT: ; uselistorder directives
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// CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 1, 0 }
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// CHECK:STDOUT:
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// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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// CHECK:STDOUT: attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
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// CHECK:STDOUT:
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// CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
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// CHECK:STDOUT: !llvm.dbg.cu = !{!2}
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// CHECK:STDOUT:
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// CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
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// CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
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// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
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// CHECK:STDOUT: !3 = !DIFile(filename: "assignment.carbon", directory: "")
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// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Main", linkageName: "_CMain.Main", scope: null, file: !3, line: 11, type: !5, spFlags: DISPFlagDefinition, unit: !2)
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// CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
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// CHECK:STDOUT: !6 = !{}
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// CHECK:STDOUT: !7 = !DILocation(line: 12, column: 7, scope: !4)
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// CHECK:STDOUT: !8 = !DILocation(line: 12, column: 3, scope: !4)
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// CHECK:STDOUT: !9 = !DILocation(line: 13, column: 3, scope: !4)
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// CHECK:STDOUT: !10 = !DILocation(line: 15, column: 7, scope: !4)
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// CHECK:STDOUT: !11 = !DILocation(line: 15, column: 3, scope: !4)
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// CHECK:STDOUT: !12 = !DILocation(line: 11, column: 1, scope: !4)
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