[AArch64] Map G_LOAD on FPR when the definition goes to a copy to FPR

We used to detect loads feeding fp instructions, but we were
failing to take into account cases where this happens through copies.
For instance, loads can fed copies coming from the ABI lowering
of floating point arguments/results.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@318589 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 5 insertions, 2 deletions

diff --git a/test/CodeGen/AArch64/GlobalISel/arm64-regbankselect.mir b/test/CodeGen/AArch64/GlobalISel/arm64-regbankselect.mir
index aace553af2d..a27cf2bea78 100644
--- a/test/CodeGen/AArch64/GlobalISel/arm64-regbankselect.mir
+++ b/test/CodeGen/AArch64/GlobalISel/arm64-regbankselect.mir
@@ -917,7 +917,7 @@ body:             |
 # CHECK: registers:
 # CHECK:  - { id: 0, class: fpr, preferred-register: '' }
 # CHECK:  - { id: 1, class: gpr, preferred-register: '' }
-# CHECK:  - { id: 2, class: gpr, preferred-register: '' }
+# CHECK:  - { id: 2, class: fpr, preferred-register: '' }
 #
 # CHECK:  %0:fpr(s16) = COPY %h0
 # CHECK-NEXT: %1:gpr(p0) = G_FRAME_INDEX %stack.0.p.addr
@@ -925,7 +925,10 @@ body:             |
 # would have been on GPR and we would have to insert a copy to move
 # the value away from FPR (h0).
 # CHECK-NEXT: G_STORE %0(s16), %1(p0) :: (store 2 into %ir.p.addr)
-# CHECK-NEXT: %2:gpr(s16) = G_LOAD %1(p0) :: (load 2 from %ir.p.addr)
+# If we didn't look through the copy for %2, the default mapping
+# would have been on GPR and we would have to insert a copy to move
+# the value to FPR (h0).
+# CHECK-NEXT: %2:fpr(s16) = G_LOAD %1(p0) :: (load 2 from %ir.p.addr)
 # CHECK-NEXT: %h0 = COPY %2(s16)
 name:            passFp16ViaAllocas
 alignment:       2