From f6bae1e434dd42b06f711f8b6652ec4173a8097c Mon Sep 17 00:00:00 2001 From: Richard Sandiford Date: Tue, 2 Jul 2013 15:28:56 +0000 Subject: [SystemZ] Use MVC to spill loads and stores Try to use MVC when spilling the destination of a simple load or the source of a simple store. As explained in the comment, this doesn't yet handle the case where the load or store location is also a frame index, since that could lead to two simultaneous scavenger spills, something the backend can't handle yet. spill-02.py tests that this restriction kicks in, but unfortunately I've not yet found a case that would fail without it. The volatile trick I used for other scavenger tests doesn't work here because we can't use MVC for volatile accesses anyway. I'm planning on relaxing the restriction later, hopefully with a test that does trigger the problem... Tests @f8 and @f9 also showed that L(G)RL and ST(G)RL were wrongly classified as SimpleBDX{Load,Store}. It wouldn't be easy to test for that bug separately, which is why I didn't split out the fix as a separate patch. llvm-svn: 185434 --- llvm/test/CodeGen/SystemZ/Large/spill-02.py | 46 +++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) create mode 100644 llvm/test/CodeGen/SystemZ/Large/spill-02.py (limited to 'llvm/test/CodeGen/SystemZ/Large/spill-02.py') diff --git a/llvm/test/CodeGen/SystemZ/Large/spill-02.py b/llvm/test/CodeGen/SystemZ/Large/spill-02.py new file mode 100644 index 00000000000..0eba3edecb7 --- /dev/null +++ b/llvm/test/CodeGen/SystemZ/Large/spill-02.py @@ -0,0 +1,46 @@ +# Test cases where we spill from one frame index to another, both of which +# would be out of range of MVC. At present we don't use MVC in this case. +# RUN: python %s | llc -mtriple=s390x-linux-gnu | FileCheck %s + +# There are 8 usable call-saved GPRs. The first 160 bytes of the frame +# are needed for the ABI call frame, and a further 8 bytes are needed +# for the emergency spill slot. That means we will have at least one +# out-of-range slot if: +# +# count == (4096 - 168) / 8 + 8 + 1 == 500 +# +# Add in some extra just to be sure. +# +# CHECK: f1: +# CHECK-NOT: mvc +# CHECK: br %r14 +count = 510 + +print 'declare void @foo(i64 *%base0, i64 *%base1)' +print '' +print 'define void @f1() {' + +for i in range(2): + print ' %%alloc%d = alloca [%d x i64]' % (i, count / 2) + print (' %%base%d = getelementptr [%d x i64] * %%alloc%d, i64 0, i64 0' + % (i, count / 2, i)) + +print ' call void @foo(i64 *%base0, i64 *%base1)' +print '' + +for i in range(count): + print ' %%ptr%d = getelementptr i64 *%%base%d, i64 %d' % (i, i % 2, i / 2) + print ' %%val%d = load i64 *%%ptr%d' % (i, i) + print '' + +print ' call void @foo(i64 *%base0, i64 *%base1)' +print '' + +for i in range (count): + print ' store i64 %%val%d, i64 *%%ptr%d' % (i, i) + +print '' +print ' call void @foo(i64 *%base0, i64 *%base1)' +print '' +print ' ret void' +print '}' -- cgit v1.2.3