[llvm] [AArch64] Add FeatureZCRegMoveFPR128 subtarget feature (PR #148427)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-aarch64

Author: Tomer Shafir (tomershafir)

<details>
<summary>Changes</summary>

Adds a subtarget feature called `FeatureZCRegMoveFPR128` that enables to query wether the target supports zero cycle reg move for FPR128 NEON registers, and embeds it into the appropriate processors. It prepares for a register coalescer optimization to prevent rematerialization of moves where the target supports ZCM.


---
Full diff: https://github.com/llvm/llvm-project/pull/148427.diff


2 Files Affected:

- (modified) llvm/lib/Target/AArch64/AArch64Features.td (+3) 
- (modified) llvm/lib/Target/AArch64/AArch64Processors.td (+10) 


``````````diff
diff --git a/llvm/lib/Target/AArch64/AArch64Features.td b/llvm/lib/Target/AArch64/AArch64Features.td
index 9973df865ea17..d6f9d7a8b8941 100644
--- a/llvm/lib/Target/AArch64/AArch64Features.td
+++ b/llvm/lib/Target/AArch64/AArch64Features.td
@@ -627,6 +627,9 @@ def FeatureZCRegMoveFPR64 : SubtargetFeature<"zcm-fpr64", "HasZeroCycleRegMoveFP
 def FeatureZCRegMoveFPR32 : SubtargetFeature<"zcm-fpr32", "HasZeroCycleRegMoveFPR32", "true",
                                         "Has zero-cycle register moves for FPR32 registers">;
 
+def FeatureZCRegMoveFPR128 : SubtargetFeature<"zcm-fpr128", "HasZeroCycleRegMoveFPR128", "true",
+                                        "Has zero-cycle register moves for FPR128 registers">;
+                                        
 def FeatureZCZeroingGP : SubtargetFeature<"zcz-gp", "HasZeroCycleZeroingGP", "true",
                                         "Has zero-cycle zeroing instructions for generic registers">;
 
diff --git a/llvm/lib/Target/AArch64/AArch64Processors.td b/llvm/lib/Target/AArch64/AArch64Processors.td
index 5379305bc7a7f..172b840d17ee2 100644
--- a/llvm/lib/Target/AArch64/AArch64Processors.td
+++ b/llvm/lib/Target/AArch64/AArch64Processors.td
@@ -313,6 +313,7 @@ def TuneAppleA7  : SubtargetFeature<"apple-a7", "ARMProcFamily", "AppleA7",
                                     FeatureStorePairSuppress,
                                     FeatureZCRegMoveGPR64,
                                     FeatureZCRegMoveFPR64,
+                                    FeatureZCRegMoveFPR128,
                                     FeatureZCZeroing,
                                     FeatureZCZeroingFPWorkaround]>;
 
@@ -327,6 +328,7 @@ def TuneAppleA10 : SubtargetFeature<"apple-a10", "ARMProcFamily", "AppleA10",
                                     FeatureStorePairSuppress,
                                     FeatureZCRegMoveGPR64,
                                     FeatureZCRegMoveFPR64,
+                                    FeatureZCRegMoveFPR128,
                                     FeatureZCZeroing]>;
 
 def TuneAppleA11 : SubtargetFeature<"apple-a11", "ARMProcFamily", "AppleA11",
@@ -340,6 +342,7 @@ def TuneAppleA11 : SubtargetFeature<"apple-a11", "ARMProcFamily", "AppleA11",
                                     FeatureStorePairSuppress,
                                     FeatureZCRegMoveGPR64,
                                     FeatureZCRegMoveFPR64,
+                                    FeatureZCRegMoveFPR128,
                                     FeatureZCZeroing]>;
 
 def TuneAppleA12 : SubtargetFeature<"apple-a12", "ARMProcFamily", "AppleA12",
@@ -353,6 +356,7 @@ def TuneAppleA12 : SubtargetFeature<"apple-a12", "ARMProcFamily", "AppleA12",
                                     FeatureStorePairSuppress,
                                     FeatureZCRegMoveGPR64,
                                     FeatureZCRegMoveFPR64,
+                                    FeatureZCRegMoveFPR128,
                                     FeatureZCZeroing]>;
 
 def TuneAppleA13 : SubtargetFeature<"apple-a13", "ARMProcFamily", "AppleA13",
@@ -366,6 +370,7 @@ def TuneAppleA13 : SubtargetFeature<"apple-a13", "ARMProcFamily", "AppleA13",
                                     FeatureStorePairSuppress,
                                     FeatureZCRegMoveGPR64,
                                     FeatureZCRegMoveFPR64,
+                                    FeatureZCRegMoveFPR128,
                                     FeatureZCZeroing]>;
 
 def TuneAppleA14 : SubtargetFeature<"apple-a14", "ARMProcFamily", "AppleA14",
@@ -384,6 +389,7 @@ def TuneAppleA14 : SubtargetFeature<"apple-a14", "ARMProcFamily", "AppleA14",
                                     FeatureStorePairSuppress,
                                     FeatureZCRegMoveGPR64,
                                     FeatureZCRegMoveFPR64,
+                                    FeatureZCRegMoveFPR128,
                                     FeatureZCZeroing]>;
 
 def TuneAppleA15 : SubtargetFeature<"apple-a15", "ARMProcFamily", "AppleA15",
@@ -402,6 +408,7 @@ def TuneAppleA15 : SubtargetFeature<"apple-a15", "ARMProcFamily", "AppleA15",
                                     FeatureStorePairSuppress,
                                     FeatureZCRegMoveGPR64,
                                     FeatureZCRegMoveFPR64,
+                                    FeatureZCRegMoveFPR128,
                                     FeatureZCZeroing]>;
 
 def TuneAppleA16 : SubtargetFeature<"apple-a16", "ARMProcFamily", "AppleA16",
@@ -420,6 +427,7 @@ def TuneAppleA16 : SubtargetFeature<"apple-a16", "ARMProcFamily", "AppleA16",
                                     FeatureStorePairSuppress,
                                     FeatureZCRegMoveGPR64,
                                     FeatureZCRegMoveFPR64,
+                                    FeatureZCRegMoveFPR128,
                                     FeatureZCZeroing]>;
 
 def TuneAppleA17 : SubtargetFeature<"apple-a17", "ARMProcFamily", "AppleA17",
@@ -438,6 +446,7 @@ def TuneAppleA17 : SubtargetFeature<"apple-a17", "ARMProcFamily", "AppleA17",
                                     FeatureStorePairSuppress,
                                     FeatureZCRegMoveGPR64,
                                     FeatureZCRegMoveFPR64,
+                                    FeatureZCRegMoveFPR128,
                                     FeatureZCZeroing]>;
 
 def TuneAppleM4 : SubtargetFeature<"apple-m4", "ARMProcFamily", "AppleM4",
@@ -455,6 +464,7 @@ def TuneAppleM4 : SubtargetFeature<"apple-m4", "ARMProcFamily", "AppleM4",
                                      FeatureFuseLiterals,
                                      FeatureZCRegMoveGPR64,
                                      FeatureZCRegMoveFPR64,
+                                     FeatureZCRegMoveFPR128,
                                      FeatureZCZeroing
                                      ]>;
 

``````````

</details>


https://github.com/llvm/llvm-project/pull/148427