[llvm] [LLVM][CodeGen][AArch64] Fix global-isel for LD1R. (PR #164418)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-aarch64

Author: Paul Walker (paulwalker-arm)

<details>
<summary>Changes</summary>

LD1Rv8b only supports a base register but the DAG is matched using am_indexed8 with the offset it finds silently dropped.

I've also fixed a couple of immediate operands types inconsistencies that don't manifest as bugs because their incorrect scaling is overriden by the complex pattern and MachineInstr that are correct and thus there's nothing to test.

---
Full diff: https://github.com/llvm/llvm-project/pull/164418.diff


3 Files Affected:

- (modified) llvm/lib/Target/AArch64/AArch64InstrAtomics.td (+6-6) 
- (modified) llvm/lib/Target/AArch64/AArch64InstrGISel.td (+1-1) 
- (modified) llvm/test/CodeGen/AArch64/arm64-ld1.ll (+8-18) 


``````````diff
diff --git a/llvm/lib/Target/AArch64/AArch64InstrAtomics.td b/llvm/lib/Target/AArch64/AArch64InstrAtomics.td
index 31fcd63b9f2c8..5d9215dd71233 100644
--- a/llvm/lib/Target/AArch64/AArch64InstrAtomics.td
+++ b/llvm/lib/Target/AArch64/AArch64InstrAtomics.td
@@ -136,8 +136,8 @@ def : Pat<(f32 (bitconvert (i32 (relaxed_load<atomic_load_nonext_32>
                (ro_Xindexed32 GPR64sp:$Rn, GPR64:$Rm, ro_Xextend32:$extend))))),
           (LDRSroX GPR64sp:$Rn, GPR64:$Rm, ro_Xextend32:$extend)>;
 def : Pat<(f32 (bitconvert (i32 (relaxed_load<atomic_load_nonext_32>
-               (am_indexed32 GPR64sp:$Rn, uimm12s8:$offset))))),
-          (LDRSui GPR64sp:$Rn, uimm12s8:$offset)>;
+               (am_indexed32 GPR64sp:$Rn, uimm12s4:$offset))))),
+          (LDRSui GPR64sp:$Rn, uimm12s4:$offset)>;
 def : Pat<(f32 (bitconvert (i32 (relaxed_load<atomic_load_nonext_32>
                (am_unscaled32 GPR64sp:$Rn, simm9:$offset))))),
           (LDURSi GPR64sp:$Rn, simm9:$offset)>;
@@ -236,11 +236,11 @@ def : Pat<(relaxed_store<atomic_store_32>
 def : Pat<(releasing_store<atomic_store_64> GPR64sp:$ptr, GPR64:$val),
           (STLRX GPR64:$val, GPR64sp:$ptr)>;
 def : Pat<(relaxed_store<atomic_store_64> (ro_Windexed64 GPR64sp:$Rn, GPR32:$Rm,
-                                                         ro_Wextend16:$extend),
+                                                         ro_Wextend64:$extend),
                                           GPR64:$val),
           (STRXroW GPR64:$val, GPR64sp:$Rn, GPR32:$Rm, ro_Wextend64:$extend)>;
 def : Pat<(relaxed_store<atomic_store_64> (ro_Xindexed64 GPR64sp:$Rn, GPR64:$Rm,
-                                                         ro_Xextend16:$extend),
+                                                         ro_Xextend64:$extend),
                                           GPR64:$val),
           (STRXroX GPR64:$val, GPR64sp:$Rn, GPR64:$Rm, ro_Xextend64:$extend)>;
 def : Pat<(relaxed_store<atomic_store_64>
@@ -276,8 +276,8 @@ def : Pat<(relaxed_store<atomic_store_64> (ro_Xindexed64 GPR64sp:$Rn, GPR64:$Rm,
                                           (i64 (bitconvert (f64 FPR64Op:$val)))),
           (STRDroX FPR64Op:$val, GPR64sp:$Rn, GPR64:$Rm, ro_Xextend64:$extend)>;
 def : Pat<(relaxed_store<atomic_store_64>
-              (am_indexed64 GPR64sp:$Rn, uimm12s4:$offset), (i64 (bitconvert (f64 FPR64Op:$val)))),
-          (STRDui FPR64Op:$val, GPR64sp:$Rn, uimm12s4:$offset)>;
+              (am_indexed64 GPR64sp:$Rn, uimm12s8:$offset), (i64 (bitconvert (f64 FPR64Op:$val)))),
+          (STRDui FPR64Op:$val, GPR64sp:$Rn, uimm12s8:$offset)>;
 def : Pat<(relaxed_store<atomic_store_64>
                (am_unscaled64 GPR64sp:$Rn, simm9:$offset), (i64 (bitconvert (f64 FPR64Op:$val)))),
           (STURDi FPR64Op:$val, GPR64sp:$Rn, simm9:$offset)>;
diff --git a/llvm/lib/Target/AArch64/AArch64InstrGISel.td b/llvm/lib/Target/AArch64/AArch64InstrGISel.td
index fe8419301b306..30b7b03f7a69a 100644
--- a/llvm/lib/Target/AArch64/AArch64InstrGISel.td
+++ b/llvm/lib/Target/AArch64/AArch64InstrGISel.td
@@ -507,7 +507,7 @@ let AddedComplexity = 19 in {
   defm : VecROStoreLane64_0Pat<ro32, store, v2i32, i32, ssub, STRSroW, STRSroX>;
 }
 
-def : Pat<(v8i8 (AArch64dup (i8 (load (am_indexed8 GPR64sp:$Rn))))),
+def : Pat<(v8i8 (AArch64dup (i8 (load GPR64sp:$Rn)))),
           (LD1Rv8b GPR64sp:$Rn)>;
 def : Pat<(v16i8 (AArch64dup (i8 (load GPR64sp:$Rn)))),
           (LD1Rv16b GPR64sp:$Rn)>;
diff --git a/llvm/test/CodeGen/AArch64/arm64-ld1.ll b/llvm/test/CodeGen/AArch64/arm64-ld1.ll
index 0b22fa49cb5c1..c2b2c1ebf58fe 100644
--- a/llvm/test/CodeGen/AArch64/arm64-ld1.ll
+++ b/llvm/test/CodeGen/AArch64/arm64-ld1.ll
@@ -1654,24 +1654,14 @@ define %struct.__neon_float64x2x4_t @ld1_x4_v2f64(ptr %addr) {
 }
 
 define <8 x i8> @dup_ld1_from_stack(ptr %__ret) {
-; CHECK-SD-LABEL: dup_ld1_from_stack:
-; CHECK-SD:       // %bb.0: // %entry
-; CHECK-SD-NEXT:    sub sp, sp, #16
-; CHECK-SD-NEXT:    .cfi_def_cfa_offset 16
-; CHECK-SD-NEXT:    add x8, sp, #15
-; CHECK-SD-NEXT:    ld1r.8b { v0 }, [x8]
-; CHECK-SD-NEXT:    add sp, sp, #16
-; CHECK-SD-NEXT:    ret
-;
-; CHECK-GI-LABEL: dup_ld1_from_stack:
-; CHECK-GI:       // %bb.0: // %entry
-; CHECK-GI-NEXT:    str x29, [sp, #-16]! // 8-byte Folded Spill
-; CHECK-GI-NEXT:    .cfi_def_cfa_offset 16
-; CHECK-GI-NEXT:    .cfi_offset w29, -16
-; CHECK-GI-NEXT:    add x8, sp, #15
-; CHECK-GI-NEXT:    ld1r.8b { v0 }, [x8]
-; CHECK-GI-NEXT:    ldr x29, [sp], #16 // 8-byte Folded Reload
-; CHECK-GI-NEXT:    ret
+; CHECK-LABEL: dup_ld1_from_stack:
+; CHECK:       // %bb.0: // %entry
+; CHECK-NEXT:    sub sp, sp, #16
+; CHECK-NEXT:    .cfi_def_cfa_offset 16
+; CHECK-NEXT:    add x8, sp, #15
+; CHECK-NEXT:    ld1r.8b { v0 }, [x8]
+; CHECK-NEXT:    add sp, sp, #16
+; CHECK-NEXT:    ret
 entry:
   %item = alloca i8, align 1
   %0 = load i8, ptr %item, align 1

``````````

</details>


https://github.com/llvm/llvm-project/pull/164418