llvm-6502/test/Transforms/RewriteStatepointsForGC/base-pointers-3.ll
Philip Reames a3f59e44cd [RewriteStatepointsForGC] Add tests for the base pointer identification algorithm
These tests cover the 'base object' identification and rewritting portion of RewriteStatepointsForGC.  These aren't completely exhaustive, but they've proven to be reasonable effective over time at finding regressions.

In the process of porting these tests over, I found my first "cleanup per llvm code style standards" bug.  We were relying on the order of iteration when testing the base pointers found for a derived pointer.  When we switched from std::set to DenseSet, this stopped being a safe assumption.  I'm suspecting I'm going to find more of those.  In particular, I'm now really wondering about the main iteration loop for this algorithm.  I need to go take a closer look at the assumptions there.

I'm not really happy with the fact these are testing what is essentially debug output (i.e. enabled via command line flags).  Suggestions for how to structure this better are very welcome.  



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230818 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-28 00:20:48 +00:00

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LLVM

; RUN: opt %s -rewrite-statepoints-for-gc -spp-print-base-pointers -S 2>&1 | FileCheck %s
; CHECK: derived %next.i64 base %base_obj
define void @test(i64 addrspace(1)* %base_obj) gc "statepoint-example" {
entry:
%obj = getelementptr i64, i64 addrspace(1)* %base_obj, i32 1
br label %loop
loop:
%current = phi i64 addrspace(1)* [ %obj, %entry ], [ %next.i64, %loop ]
%current.i32 = bitcast i64 addrspace(1)* %current to i32 addrspace(1)*
%next.i32 = getelementptr i32, i32 addrspace(1)* %current.i32, i32 1
%next.i64 = bitcast i32 addrspace(1)* %next.i32 to i64 addrspace(1)*
%safepoint_token = call i32 (void ()*, i32, i32, ...)* @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @do_safepoint, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0)
br label %loop
}
declare void @do_safepoint()
declare i32 @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()*, i32, i32, ...)