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author | Tim Northover <tnorthover@apple.com> | 2013-06-14 20:22:21 +0000 |
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committer | Tim Northover <tnorthover@apple.com> | 2013-06-14 20:22:21 +0000 |
commit | 89dbe9744255864445b1c9f9a613ae333d3f79c8 (patch) | |
tree | 65aa89308e7636e6eba9973e4f35e49711796566 /test/CodeGen/X86/remat-phys-dead.ll | |
parent | d5d7410982788be5b2e31c7e150a219f80d0a0d9 (diff) | |
download | llvm-89dbe9744255864445b1c9f9a613ae333d3f79c8.tar.gz llvm-89dbe9744255864445b1c9f9a613ae333d3f79c8.tar.bz2 llvm-89dbe9744255864445b1c9f9a613ae333d3f79c8.tar.xz |
Mark rematerialized super/sub registers as dead.
When we're rematerializing into a not-quite-right register we already add the
real definition as an imp-def, but we should also be marking the "official"
register as dead, since nothing else is going to use it as a result of this
remat.
Not doing this can affect pressure tracking.
rdar://problem/14158833
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184002 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/CodeGen/X86/remat-phys-dead.ll')
-rw-r--r-- | test/CodeGen/X86/remat-phys-dead.ll | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/test/CodeGen/X86/remat-phys-dead.ll b/test/CodeGen/X86/remat-phys-dead.ll new file mode 100644 index 0000000000..4d7ee622a3 --- /dev/null +++ b/test/CodeGen/X86/remat-phys-dead.ll @@ -0,0 +1,23 @@ +; REQUIRES: asserts +; RUN: llc -mtriple=x86_64-apple-darwin -debug -o /dev/null < %s 2>&1 | FileCheck %s + +; We need to make sure that rematerialization into a physical register marks the +; super- or sub-register as dead after this rematerialization since only the +; original register is actually used later. Largely irrelevant for a trivial +; example like this, since EAX is never used again, but easy to test. + +define i8 @test_remat() { + ret i8 0 +; CHECK: REGISTER COALESCING +; CHECK: Remat: %EAX<def,dead> = MOV32r0 %EFLAGS<imp-def,dead>, %AL<imp-def> +} + +; On the other hand, if it's already the correct width, we really shouldn't be +; marking the definition register as dead. + +define i32 @test_remat32() { + ret i32 0 +; CHECK: REGISTER COALESCING +; CHECK: Remat: %EAX<def> = MOV32r0 %EFLAGS<imp-def,dead> +} + |