From 9969458b1673648394fce3f50f3f4a84071c7ca7 Mon Sep 17 00:00:00 2001 From: Nuno Lopes Date: Fri, 6 Jul 2012 23:09:25 +0000 Subject: teach instcombine to remove allocated buffers even if there are stores, memcpy/memmove/memset, and objectsize users. This means we can do cheap DSE for heap memory. Nothing is done if the pointer excapes or has a load. The churn in the tests is mostly due to objectsize, since we want to make sure we don't delete the malloc call before evaluating the objectsize (otherwise it becomes -1/0) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159876 91177308-0d34-0410-b5e6-96231b3b80d8 --- test/Transforms/InstCombine/malloc-free-delete.ll | 53 +++++++++++++++++++++-- 1 file changed, 49 insertions(+), 4 deletions(-) (limited to 'test/Transforms/InstCombine/malloc-free-delete.ll') diff --git a/test/Transforms/InstCombine/malloc-free-delete.ll b/test/Transforms/InstCombine/malloc-free-delete.ll index eae973df0a..4e3217dc2d 100644 --- a/test/Transforms/InstCombine/malloc-free-delete.ll +++ b/test/Transforms/InstCombine/malloc-free-delete.ll @@ -1,17 +1,17 @@ ; RUN: opt < %s -instcombine -S | FileCheck %s ; PR1201 define i32 @main(i32 %argc, i8** %argv) { +; CHECK: @main %c_19 = alloca i8* %malloc_206 = tail call i8* @malloc(i32 mul (i32 ptrtoint (i8* getelementptr (i8* null, i32 1) to i32), i32 10)) store i8* %malloc_206, i8** %c_19 %tmp_207 = load i8** %c_19 tail call void @free(i8* %tmp_207) ret i32 0 -; CHECK-NOT: malloc -; CHECK-NOT: free -; CHECK: ret i32 0 +; CHECK-NEXT: ret i32 0 } +declare noalias i8* @calloc(i32, i32) nounwind declare noalias i8* @malloc(i32) declare void @free(i8*) @@ -26,13 +26,24 @@ define i1 @foo() { declare void @llvm.lifetime.start(i64, i8*) declare void @llvm.lifetime.end(i64, i8*) +declare i64 @llvm.objectsize.i64(i8*, i1) +declare void @llvm.memcpy.p0i8.p0i8.i32(i8* nocapture, i8* nocapture, i32, i32, i1) nounwind +declare void @llvm.memmove.p0i8.p0i8.i32(i8* nocapture, i8* nocapture, i32, i32, i1) nounwind +declare void @llvm.memset.p0i8.i32(i8*, i8, i32, i32, i1) nounwind -define void @test3() { +define void @test3(i8* %src) { ; CHECK: @test3 ; CHECK-NEXT: ret void %a = call noalias i8* @malloc(i32 10) call void @llvm.lifetime.start(i64 10, i8* %a) call void @llvm.lifetime.end(i64 10, i8* %a) + %size = call i64 @llvm.objectsize.i64(i8* %a, i1 true) + store i8 42, i8* %a + call void @llvm.memcpy.p0i8.p0i8.i32(i8* %a, i8* %src, i32 32, i32 1, i1 false) + call void @llvm.memmove.p0i8.p0i8.i32(i8* %a, i8* %src, i32 32, i32 1, i1 false) + call void @llvm.memset.p0i8.i32(i8* %a, i8 5, i32 32, i32 1, i1 false) + %alloc2 = call noalias i8* @calloc(i32 5, i32 7) nounwind + %z = icmp ne i8* %alloc2, null ret void } @@ -46,3 +57,37 @@ define void @test4() { call void @free(i8* %C) ret void } + +; CHECK: @test5 +define void @test5(i8* %ptr, i8** %esc) { +; CHECK-NEXT: call i8* @malloc +; CHECK-NEXT: call i8* @malloc +; CHECK-NEXT: call i8* @malloc +; CHECK-NEXT: call i8* @malloc +; CHECK-NEXT: call i8* @malloc +; CHECK-NEXT: call i8* @malloc +; CHECK-NEXT: call i8* @malloc +; CHECK-NEXT: call void @llvm.memcpy +; CHECK-NEXT: call void @llvm.memmove +; CHECK-NEXT: store +; CHECK-NEXT: call void @llvm.memcpy +; CHECK-NEXT: call void @llvm.memmove +; CHECK-NEXT: call void @llvm.memset +; CHECK-NEXT: store volatile +; CHECK-NEXT: ret + %a = call i8* @malloc(i32 700) + %b = call i8* @malloc(i32 700) + %c = call i8* @malloc(i32 700) + %d = call i8* @malloc(i32 700) + %e = call i8* @malloc(i32 700) + %f = call i8* @malloc(i32 700) + %g = call i8* @malloc(i32 700) + call void @llvm.memcpy.p0i8.p0i8.i32(i8* %ptr, i8* %a, i32 32, i32 1, i1 false) + call void @llvm.memmove.p0i8.p0i8.i32(i8* %ptr, i8* %b, i32 32, i32 1, i1 false) + store i8* %c, i8** %esc + call void @llvm.memcpy.p0i8.p0i8.i32(i8* %d, i8* %ptr, i32 32, i32 1, i1 true) + call void @llvm.memmove.p0i8.p0i8.i32(i8* %e, i8* %ptr, i32 32, i32 1, i1 true) + call void @llvm.memset.p0i8.i32(i8* %f, i8 5, i32 32, i32 1, i1 true) + store volatile i8 4, i8* %g + ret void +} -- cgit v1.2.3