[llvm] [RISCV][ISel] Add codegen support for the experimental zabha extension (PR #80192)

[Craig Topper via llvm-commits]

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@@ -2387,26 +3126,80 @@ define i8 @atomicrmw_nand_i8_monotonic(ptr %a, i8 %b) nounwind {
 ; RV64I-NEXT:    addi sp, sp, 16
 ; RV64I-NEXT:    ret
 ;
-; RV64IA-LABEL: atomicrmw_nand_i8_monotonic:
-; RV64IA:       # %bb.0:
-; RV64IA-NEXT:    andi a2, a0, -4
-; RV64IA-NEXT:    slli a0, a0, 3
-; RV64IA-NEXT:    li a3, 255
-; RV64IA-NEXT:    sllw a3, a3, a0
-; RV64IA-NEXT:    andi a1, a1, 255
-; RV64IA-NEXT:    sllw a1, a1, a0
-; RV64IA-NEXT:  .LBB30_1: # =>This Inner Loop Header: Depth=1
-; RV64IA-NEXT:    lr.w a4, (a2)
-; RV64IA-NEXT:    and a5, a4, a1
-; RV64IA-NEXT:    not a5, a5
-; RV64IA-NEXT:    xor a5, a4, a5
-; RV64IA-NEXT:    and a5, a5, a3
-; RV64IA-NEXT:    xor a5, a4, a5
-; RV64IA-NEXT:    sc.w a5, a5, (a2)
-; RV64IA-NEXT:    bnez a5, .LBB30_1
-; RV64IA-NEXT:  # %bb.2:
-; RV64IA-NEXT:    srlw a0, a4, a0
-; RV64IA-NEXT:    ret
+; RV64IA-WMO-LABEL: atomicrmw_nand_i8_monotonic:
+; RV64IA-WMO:       # %bb.0:
+; RV64IA-WMO-NEXT:    andi a2, a0, -4
+; RV64IA-WMO-NEXT:    slli a0, a0, 3
+; RV64IA-WMO-NEXT:    li a3, 255
+; RV64IA-WMO-NEXT:    sllw a3, a3, a0
+; RV64IA-WMO-NEXT:    andi a1, a1, 255
+; RV64IA-WMO-NEXT:    sllw a1, a1, a0
+; RV64IA-WMO-NEXT:  .LBB30_1: # =>This Inner Loop Header: Depth=1
+; RV64IA-WMO-NEXT:    lr.w a4, (a2)
+; RV64IA-WMO-NEXT:    and a5, a4, a1
+; RV64IA-WMO-NEXT:    not a5, a5
+; RV64IA-WMO-NEXT:    xor a5, a4, a5
+; RV64IA-WMO-NEXT:    and a5, a5, a3
+; RV64IA-WMO-NEXT:    xor a5, a4, a5
+; RV64IA-WMO-NEXT:    sc.w a5, a5, (a2)
+; RV64IA-WMO-NEXT:    bnez a5, .LBB30_1
+; RV64IA-WMO-NEXT:  # %bb.2:
+; RV64IA-WMO-NEXT:    srlw a0, a4, a0
+; RV64IA-WMO-NEXT:    ret
+;
+; RV64IA-ZABHA-LABEL: atomicrmw_nand_i8_monotonic:
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topperc wrote:

I don't think this code is correct. We're not building the mask correctly. We're still using lr.w/sc.w so we still need to build the same code we do for just the A extension.

https://github.com/llvm/llvm-project/pull/80192