From 4ca00df57189d95b282cfc6296a51bc1058e670a Mon Sep 17 00:00:00 2001 From: Nikita Popov Date: Fri, 7 Dec 2018 21:16:52 +0000 Subject: [PATCH] [MemCpyOpt] Add tests for memset->memcpy forwaring with undef tail; NFC These are baseline tests for D55120. llvm-svn: 348644 --- .../MemCpyOpt/memset-memcpy-oversized.ll | 152 +++++++++++++++++++++ 1 file changed, 152 insertions(+) create mode 100644 llvm/test/Transforms/MemCpyOpt/memset-memcpy-oversized.ll diff --git a/llvm/test/Transforms/MemCpyOpt/memset-memcpy-oversized.ll b/llvm/test/Transforms/MemCpyOpt/memset-memcpy-oversized.ll new file mode 100644 index 0000000..39538be --- /dev/null +++ b/llvm/test/Transforms/MemCpyOpt/memset-memcpy-oversized.ll @@ -0,0 +1,152 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; RUN: opt -memcpyopt -S %s | FileCheck %s + +; memset -> memcpy forwarding, if memcpy is larger than memset, but trailing +; bytes are known to be undef. + + +%T = type { i64, i32, i32 } + +define void @test_alloca(i8* %result) { +; CHECK-LABEL: @test_alloca( +; CHECK-NEXT: [[A:%.*]] = alloca [[T:%.*]], align 8 +; CHECK-NEXT: [[B:%.*]] = bitcast %T* [[A]] to i8* +; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* align 8 [[B]], i8 0, i64 12, i1 false) +; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* [[RESULT:%.*]], i8* align 8 [[B]], i64 16, i1 false) +; CHECK-NEXT: ret void +; + %a = alloca %T, align 8 + %b = bitcast %T* %a to i8* + call void @llvm.memset.p0i8.i64(i8* align 8 %b, i8 0, i64 12, i1 false) + call void @llvm.memcpy.p0i8.p0i8.i64(i8* %result, i8* align 8 %b, i64 16, i1 false) + ret void +} + +define void @test_alloca_with_lifetimes(i8* %result) { +; CHECK-LABEL: @test_alloca_with_lifetimes( +; CHECK-NEXT: [[A:%.*]] = alloca [[T:%.*]], align 8 +; CHECK-NEXT: [[B:%.*]] = bitcast %T* [[A]] to i8* +; CHECK-NEXT: call void @llvm.lifetime.start.p0i8(i64 16, i8* [[B]]) +; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* align 8 [[B]], i8 0, i64 12, i1 false) +; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* [[RESULT:%.*]], i8* align 8 [[B]], i64 16, i1 false) +; CHECK-NEXT: call void @llvm.lifetime.end.p0i8(i64 16, i8* [[B]]) +; CHECK-NEXT: ret void +; + %a = alloca %T, align 8 + %b = bitcast %T* %a to i8* + call void @llvm.lifetime.start.p0i8(i64 16, i8* %b) + call void @llvm.memset.p0i8.i64(i8* align 8 %b, i8 0, i64 12, i1 false) + call void @llvm.memcpy.p0i8.p0i8.i64(i8* %result, i8* align 8 %b, i64 16, i1 false) + call void @llvm.lifetime.end.p0i8(i64 16, i8* %b) + ret void +} + +define void @test_malloc_with_lifetimes(i8* %result) { +; CHECK-LABEL: @test_malloc_with_lifetimes( +; CHECK-NEXT: [[A:%.*]] = call i8* @malloc(i64 16) +; CHECK-NEXT: call void @llvm.lifetime.start.p0i8(i64 16, i8* [[A]]) +; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* align 8 [[A]], i8 0, i64 12, i1 false) +; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* [[RESULT:%.*]], i8* align 8 [[A]], i64 16, i1 false) +; CHECK-NEXT: call void @llvm.lifetime.end.p0i8(i64 16, i8* [[A]]) +; CHECK-NEXT: call void @free(i8* [[A]]) +; CHECK-NEXT: ret void +; + %a = call i8* @malloc(i64 16) + call void @llvm.lifetime.start.p0i8(i64 16, i8* %a) + call void @llvm.memset.p0i8.i64(i8* align 8 %a, i8 0, i64 12, i1 false) + call void @llvm.memcpy.p0i8.p0i8.i64(i8* %result, i8* align 8 %a, i64 16, i1 false) + call void @llvm.lifetime.end.p0i8(i64 16, i8* %a) + call void @free(i8* %a) + ret void +} + +; memcpy size is larger than lifetime, don't optimize. +define void @test_copy_larger_than_lifetime_size(i8* %result) { +; CHECK-LABEL: @test_copy_larger_than_lifetime_size( +; CHECK-NEXT: [[A:%.*]] = call i8* @malloc(i64 16) +; CHECK-NEXT: call void @llvm.lifetime.start.p0i8(i64 12, i8* [[A]]) +; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* align 8 [[A]], i8 0, i64 12, i1 false) +; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* [[RESULT:%.*]], i8* align 8 [[A]], i64 16, i1 false) +; CHECK-NEXT: call void @llvm.lifetime.end.p0i8(i64 12, i8* [[A]]) +; CHECK-NEXT: call void @free(i8* [[A]]) +; CHECK-NEXT: ret void +; + %a = call i8* @malloc(i64 16) + call void @llvm.lifetime.start.p0i8(i64 12, i8* %a) + call void @llvm.memset.p0i8.i64(i8* align 8 %a, i8 0, i64 12, i1 false) + call void @llvm.memcpy.p0i8.p0i8.i64(i8* %result, i8* align 8 %a, i64 16, i1 false) + call void @llvm.lifetime.end.p0i8(i64 12, i8* %a) + call void @free(i8* %a) + ret void +} + +; The trailing bytes are not known to be undef, we can't ignore them. +define void @test_not_undef_memory(i8* %result, i8* %input) { +; CHECK-LABEL: @test_not_undef_memory( +; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* align 8 [[INPUT:%.*]], i8 0, i64 12, i1 false) +; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* [[RESULT:%.*]], i8* align 8 [[INPUT]], i64 16, i1 false) +; CHECK-NEXT: ret void +; + call void @llvm.memset.p0i8.i64(i8* align 8 %input, i8 0, i64 12, i1 false) + call void @llvm.memcpy.p0i8.p0i8.i64(i8* %result, i8* align 8 %input, i64 16, i1 false) + ret void +} + +; Memset is volatile, memcpy is not. Can be optimized. +define void @test_volatile_memset(i8* %result) { +; CHECK-LABEL: @test_volatile_memset( +; CHECK-NEXT: [[A:%.*]] = alloca [[T:%.*]], align 8 +; CHECK-NEXT: [[B:%.*]] = bitcast %T* [[A]] to i8* +; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* align 8 [[B]], i8 0, i64 12, i1 true) +; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* [[RESULT:%.*]], i8* align 8 [[B]], i64 16, i1 false) +; CHECK-NEXT: ret void +; + %a = alloca %T, align 8 + %b = bitcast %T* %a to i8* + call void @llvm.memset.p0i8.i64(i8* align 8 %b, i8 0, i64 12, i1 true) + call void @llvm.memcpy.p0i8.p0i8.i64(i8* %result, i8* align 8 %b, i64 16, i1 false) + ret void +} + +; Memcpy is volatile, memset is not. Cannot be optimized. +define void @test_volatile_memcpy(i8* %result) { +; CHECK-LABEL: @test_volatile_memcpy( +; CHECK-NEXT: [[A:%.*]] = alloca [[T:%.*]], align 8 +; CHECK-NEXT: [[B:%.*]] = bitcast %T* [[A]] to i8* +; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* align 8 [[B]], i8 0, i64 12, i1 false) +; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* [[RESULT:%.*]], i8* align 8 [[B]], i64 16, i1 true) +; CHECK-NEXT: ret void +; + %a = alloca %T, align 8 + %b = bitcast %T* %a to i8* + call void @llvm.memset.p0i8.i64(i8* align 8 %b, i8 0, i64 12, i1 false) + call void @llvm.memcpy.p0i8.p0i8.i64(i8* %result, i8* align 8 %b, i64 16, i1 true) + ret void +} + +; Write between memset and memcpy, can't optimize. +define void @test_write_between(i8* %result) { +; CHECK-LABEL: @test_write_between( +; CHECK-NEXT: [[A:%.*]] = alloca [[T:%.*]], align 8 +; CHECK-NEXT: [[B:%.*]] = bitcast %T* [[A]] to i8* +; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* align 8 [[B]], i8 0, i64 12, i1 false) +; CHECK-NEXT: store i8 -1, i8* [[B]] +; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* [[RESULT:%.*]], i8* align 8 [[B]], i64 16, i1 false) +; CHECK-NEXT: ret void +; + %a = alloca %T, align 8 + %b = bitcast %T* %a to i8* + call void @llvm.memset.p0i8.i64(i8* align 8 %b, i8 0, i64 12, i1 false) + store i8 -1, i8* %b + call void @llvm.memcpy.p0i8.p0i8.i64(i8* %result, i8* align 8 %b, i64 16, i1 false) + ret void +} + +declare i8* @malloc(i64) +declare void @free(i8*) + +declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i1) +declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture readonly, i64, i1) + +declare void @llvm.lifetime.start.p0i8(i64, i8* nocapture) +declare void @llvm.lifetime.end.p0i8(i64, i8* nocapture) -- 2.7.4