[llvm] 1366071 - [AArch64] Modeling NZCV read/write for MOPS instructions

[via llvm-commits]

Author: tyb0807
Date: 2022-01-31T20:50:16Z
New Revision: 13660715e677919d9a89dc6a3a77532593c3c7f6

URL: https://github.com/llvm/llvm-project/commit/13660715e677919d9a89dc6a3a77532593c3c7f6
DIFF: https://github.com/llvm/llvm-project/commit/13660715e677919d9a89dc6a3a77532593c3c7f6.diff

LOG: [AArch64] Modeling NZCV read/write for MOPS instructions

According to the specification, MOPS instructions define/use NZCV flags as
part of their semantics (see discussion in
https://reviews.llvm.org/D116157).

More specifically, the specification of the MOPS extension states that
each memcpy/memset/memmov operation will be performed by a series
of three MOPS instructions P, M and E. The P instruction writes to the
NZCV flags, while the others (M and E) reads from the NZCV flags.

This is part 2/4 of a series of patches split from
https://reviews.llvm.org/D117405 to facilitate reviewing.

Differential Revision: https://reviews.llvm.org/D117757

Added: 
    

Modified: 
    llvm/lib/Target/AArch64/AArch64InstrInfo.td

Removed: 
    


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diff  --git a/llvm/lib/Target/AArch64/AArch64InstrInfo.td b/llvm/lib/Target/AArch64/AArch64InstrInfo.td
index 740ebd52b85f..91baf4cd11e0 100644
--- a/llvm/lib/Target/AArch64/AArch64InstrInfo.td
+++ b/llvm/lib/Target/AArch64/AArch64InstrInfo.td
@@ -8333,23 +8333,33 @@ let Predicates = [HasLS64] in {
 }
 
 let Predicates = [HasMOPS] in {
-  defm CPYFP : MOPSMemoryCopyInsns<0b00, "cpyfp">;
-  defm CPYFM : MOPSMemoryCopyInsns<0b01, "cpyfm">;
-  defm CPYFE : MOPSMemoryCopyInsns<0b10, "cpyfe">;
+  let Defs = [NZCV] in {
+    defm CPYFP : MOPSMemoryCopyInsns<0b00, "cpyfp">;
 
-  defm CPYP : MOPSMemoryMoveInsns<0b00, "cpyp">;
-  defm CPYM : MOPSMemoryMoveInsns<0b01, "cpym">;
-  defm CPYE : MOPSMemoryMoveInsns<0b10, "cpye">;
+    defm CPYP : MOPSMemoryMoveInsns<0b00, "cpyp">;
 
-  defm SETP : MOPSMemorySetInsns<0b00, "setp">;
-  defm SETM : MOPSMemorySetInsns<0b01, "setm">;
-  defm SETE : MOPSMemorySetInsns<0b10, "sete">;
+    defm SETP : MOPSMemorySetInsns<0b00, "setp">;
+  }
+  let Uses = [NZCV] in {
+    defm CPYFM : MOPSMemoryCopyInsns<0b01, "cpyfm">;
+    defm CPYFE : MOPSMemoryCopyInsns<0b10, "cpyfe">;
+
+    defm CPYM : MOPSMemoryMoveInsns<0b01, "cpym">;
+    defm CPYE : MOPSMemoryMoveInsns<0b10, "cpye">;
+
+    defm SETM : MOPSMemorySetInsns<0b01, "setm">;
+    defm SETE : MOPSMemorySetInsns<0b10, "sete">;
+  }
 }
 let Predicates = [HasMOPS, HasMTE] in {
-  defm SETGP     : MOPSMemorySetTaggingInsns<0b00, "setgp">;
-  defm SETGM     : MOPSMemorySetTaggingInsns<0b01, "setgm">;
-  // Can't use SETGE because it's a reserved name in TargetSelectionDAG.td
-  defm MOPSSETGE : MOPSMemorySetTaggingInsns<0b10, "setge">;
+  let Defs = [NZCV] in {
+    defm SETGP     : MOPSMemorySetTaggingInsns<0b00, "setgp">;
+  }
+  let Uses = [NZCV] in {
+    defm SETGM     : MOPSMemorySetTaggingInsns<0b01, "setgm">;
+    // Can't use SETGE because it's a reserved name in TargetSelectionDAG.td
+    defm MOPSSETGE : MOPSMemorySetTaggingInsns<0b10, "setge">;
+  }
 }
 
 let Defs = [X16, X17], mayStore = 1, isCodeGenOnly = 1 in