[llvm] [RISCV][GISel] Add really basic support for FP regbank selection for G_LOAD/G_STORE. (PR #70896)

[Craig Topper via llvm-commits]

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@@ -0,0 +1,170 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -mtriple=riscv32 -mattr=+d -run-pass=regbankselect \
+# RUN:   -simplify-mir -verify-machineinstrs %s \
+# RUN:   -o - | FileCheck %s --check-prefixes=CHECK,RV32
+# RUN: llc -mtriple=riscv64 -mattr=+d -run-pass=regbankselect \
+# RUN:   -simplify-mir -verify-machineinstrs %s \
+# RUN:   -o - | FileCheck %s --check-prefixes=CHECK,RV64
+
+---
+name:            fp_store_fp_def_f32
+legalized:       true
+tracksRegLiveness: true
+body:             |
+  bb.1:
+    liveins: $x10, $f10_f, $f11_f
+
+    ; CHECK-LABEL: name: fp_store_fp_def_f32
+    ; CHECK: liveins: $x10, $f10_f, $f11_f
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:gprb(p0) = COPY $x10
+    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:fprb(s32) = COPY $f10_f
+    ; CHECK-NEXT: [[COPY2:%[0-9]+]]:fprb(s32) = COPY $f11_f
+    ; CHECK-NEXT: [[FADD:%[0-9]+]]:fprb(s32) = G_FADD [[COPY1]], [[COPY2]]
+    ; CHECK-NEXT: G_STORE [[FADD]](s32), [[COPY]](p0) :: (store (s32))
+    ; CHECK-NEXT: PseudoRET
+    %0:_(p0) = COPY $x10
+    %1:_(s32) = COPY $f10_f
+    %2:_(s32) = COPY $f11_f
+    %3:_(s32) = G_FADD %1, %2
+    G_STORE %3(s32), %0(p0) :: (store (s32))
+    PseudoRET
+
+...
+---
+name:            fp_store_fp_def_f64
+legalized:       true
+tracksRegLiveness: true
+body:             |
+  bb.1:
+    liveins: $x10, $f10_d, $f11_d
+
+    ; CHECK-LABEL: name: fp_store_fp_def_f64
+    ; CHECK: liveins: $x10, $f10_d, $f11_d
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:gprb(p0) = COPY $x10
+    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:fprb(s64) = COPY $f10_d
+    ; CHECK-NEXT: [[COPY2:%[0-9]+]]:fprb(s64) = COPY $f11_d
+    ; CHECK-NEXT: [[FADD:%[0-9]+]]:fprb(s64) = G_FADD [[COPY1]], [[COPY2]]
+    ; CHECK-NEXT: G_STORE [[FADD]](s64), [[COPY]](p0) :: (store (s64))
+    ; CHECK-NEXT: PseudoRET
+    %0:_(p0) = COPY $x10
+    %1:_(s64) = COPY $f10_d
+    %2:_(s64) = COPY $f11_d
+    %3:_(s64) = G_FADD %1, %2
+    G_STORE %3(s64), %0(p0) :: (store (s64))
+    PseudoRET
+
+...
+---
+name:            fp_store_no_def_f64
+legalized:       true
+tracksRegLiveness: true
+body:             |
+  bb.1:
+    liveins: $x10, $f10_d, $f11_d
+
+    ; RV32-LABEL: name: fp_store_no_def_f64
+    ; RV32: liveins: $x10, $f10_d, $f11_d
+    ; RV32-NEXT: {{  $}}
+    ; RV32-NEXT: [[COPY:%[0-9]+]]:gprb(p0) = COPY $x10
+    ; RV32-NEXT: [[COPY1:%[0-9]+]]:fprb(s64) = COPY $f10_d
+    ; RV32-NEXT: G_STORE [[COPY1]](s64), [[COPY]](p0) :: (store (s64))
+    ; RV32-NEXT: PseudoRET
+    ;
+    ; RV64-LABEL: name: fp_store_no_def_f64
+    ; RV64: liveins: $x10, $f10_d, $f11_d
+    ; RV64-NEXT: {{  $}}
+    ; RV64-NEXT: [[COPY:%[0-9]+]]:gprb(p0) = COPY $x10
+    ; RV64-NEXT: [[COPY1:%[0-9]+]]:fprb(s64) = COPY $f10_d
+    ; RV64-NEXT: [[COPY2:%[0-9]+]]:gprb(s64) = COPY [[COPY1]](s64)
----------------
topperc wrote:

The first copy is created by call lowering, the second copy is created by regbank selection because this patch doesn't see the copy to know it should be an FP store. I'll fix that in another patch.

https://github.com/llvm/llvm-project/pull/70896