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| author | Matthias Braun <matze@braunis.de> | 2016-07-09 00:19:07 +0000 |
|---|---|---|
| committer | Matthias Braun <matze@braunis.de> | 2016-07-09 00:19:07 +0000 |
| commit | 152e7c8b1222d2af61df72c08caaa740e553cb6c (patch) | |
| tree | 7178c1d1db0b5bf2babca7793c71c079854e1156 /llvm/test/CodeGen/PowerPC/machine-combiner.ll | |
| parent | 07985809abeb97c131d37ee389ee0fea2a646516 (diff) | |
| download | bcm5719-llvm-152e7c8b1222d2af61df72c08caaa740e553cb6c.tar.gz bcm5719-llvm-152e7c8b1222d2af61df72c08caaa740e553cb6c.zip | |
VirtRegMap: Replace some identity copies with KILL instructions.
An identity COPY like this:
%AL = COPY %AL, %EAX<imp-def>
has no semantic effect, but encodes liveness information: Further users
of %EAX only depend on this instruction even though it does not define
the full register.
Replace the COPY with a KILL instruction in those cases to maintain this
liveness information. (This reverts a small part of r238588 but this
time adds a comment explaining why a KILL instruction is useful).
llvm-svn: 274952
Diffstat (limited to 'llvm/test/CodeGen/PowerPC/machine-combiner.ll')
| -rw-r--r-- | llvm/test/CodeGen/PowerPC/machine-combiner.ll | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/llvm/test/CodeGen/PowerPC/machine-combiner.ll b/llvm/test/CodeGen/PowerPC/machine-combiner.ll index 93fb2020d53..ae9e2e8cf6a 100644 --- a/llvm/test/CodeGen/PowerPC/machine-combiner.ll +++ b/llvm/test/CodeGen/PowerPC/machine-combiner.ll @@ -98,6 +98,7 @@ define <4 x float> @vector_reassociate_adds1(<4 x float> %x0, <4 x float> %x1, < ; CHECK-PWR: xvaddsp [[REG0:[0-9]+]], 34, 35 ; CHECK-PWR: xvaddsp [[REG1:[0-9]+]], 36, 37 ; CHECK-PWR: xvaddsp 34, [[REG0]], [[REG1]] +; CHECK-PWR: # kill ; CHECK-NEXT: blr %t0 = fadd <4 x float> %x0, %x1 @@ -115,6 +116,7 @@ define <4 x float> @vector_reassociate_adds2(<4 x float> %x0, <4 x float> %x1, < ; CHECK-PWR: xvaddsp [[REG0:[0-9]+]], 34, 35 ; CHECK-PWR: xvaddsp [[REG1:[0-9]+]], 36, 37 ; CHECK-PWR: xvaddsp 34, [[REG0]], [[REG1]] +; CHECK-PWR: # kill ; CHECK-NEXT: blr %t0 = fadd <4 x float> %x0, %x1 @@ -132,6 +134,7 @@ define <4 x float> @vector_reassociate_adds3(<4 x float> %x0, <4 x float> %x1, < ; CHECK-PWR: xvaddsp [[REG0:[0-9]+]], 34, 35 ; CHECK-PWR: xvaddsp [[REG1:[0-9]+]], 36, 37 ; CHECK-PWR: xvaddsp 34, [[REG0]], [[REG1]] +; CHECK-PWR: # kill ; CHECK-NEXT: blr %t0 = fadd <4 x float> %x0, %x1 @@ -149,6 +152,7 @@ define <4 x float> @vector_reassociate_adds4(<4 x float> %x0, <4 x float> %x1, < ; CHECK-PWR: xvaddsp [[REG0:[0-9]+]], 34, 35 ; CHECK-PWR: xvaddsp [[REG1:[0-9]+]], 36, 37 ; CHECK-PWR: xvaddsp 34, [[REG0]], [[REG1]] +; CHECK-PWR: # kill ; CHECK-NEXT: blr %t0 = fadd <4 x float> %x0, %x1 |
