[llvm] 39c8df3 - [RISCV] Add VendorXTHeadCondMov to useInversedSetcc. (#157758)

[via llvm-commits]

Author: Craig Topper
Date: 2025-09-09T22:47:51-07:00
New Revision: 39c8df3d0160ef26f239b1ebb49da63e36963308

URL: https://github.com/llvm/llvm-project/commit/39c8df3d0160ef26f239b1ebb49da63e36963308
DIFF: https://github.com/llvm/llvm-project/commit/39c8df3d0160ef26f239b1ebb49da63e36963308.diff

LOG: [RISCV] Add VendorXTHeadCondMov to useInversedSetcc. (#157758)

These instructions have a eqz/nez operand like Zicond and
XVentanaCondOps so the goal of using bexti seems applicable to them as
well.

Added: 
    

Modified: 
    llvm/lib/Target/RISCV/RISCVISelLowering.cpp
    llvm/test/CodeGen/RISCV/condops.ll

Removed: 
    


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diff  --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
index 46f544c0d4df5..6f260608bc0fc 100644
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -18945,7 +18945,8 @@ static SDValue useInversedSetcc(SDNode *N, SelectionDAG &DAG,
   // Replace (setcc eq (and x, C)) with (setcc ne (and x, C))) to generate
   // BEXTI, where C is power of 2.
   if (Subtarget.hasStdExtZbs() && VT.isScalarInteger() &&
-      (Subtarget.hasStdExtZicond() || Subtarget.hasVendorXVentanaCondOps())) {
+      (Subtarget.hasStdExtZicond() || Subtarget.hasVendorXVentanaCondOps() ||
+       Subtarget.hasVendorXTHeadCondMov())) {
     SDValue LHS = Cond.getOperand(0);
     SDValue RHS = Cond.getOperand(1);
     ISD::CondCode CC = cast<CondCodeSDNode>(Cond.getOperand(2))->get();

diff  --git a/llvm/test/CodeGen/RISCV/condops.ll b/llvm/test/CodeGen/RISCV/condops.ll
index 6c2ba493ffcd5..4fb3dff88017c 100644
--- a/llvm/test/CodeGen/RISCV/condops.ll
+++ b/llvm/test/CodeGen/RISCV/condops.ll
@@ -126,8 +126,7 @@ define i64 @zero_singlebit1(i64 %rs1, i64 %rs2) {
 ;
 ; RV64XTHEADCONDMOV-LABEL: zero_singlebit1:
 ; RV64XTHEADCONDMOV:       # %bb.0:
-; RV64XTHEADCONDMOV-NEXT:    lui a2, 1
-; RV64XTHEADCONDMOV-NEXT:    and a1, a1, a2
+; RV64XTHEADCONDMOV-NEXT:    bexti a1, a1, 12
 ; RV64XTHEADCONDMOV-NEXT:    th.mvnez a0, zero, a1
 ; RV64XTHEADCONDMOV-NEXT:    ret
 ;
@@ -4412,9 +4411,9 @@ define i64 @single_bit3(i80 %x, i64 %y) {
 ;
 ; RV64XTHEADCONDMOV-LABEL: single_bit3:
 ; RV64XTHEADCONDMOV:       # %bb.0: # %entry
-; RV64XTHEADCONDMOV-NEXT:    slli a1, a1, 63
-; RV64XTHEADCONDMOV-NEXT:    srai a0, a1, 63
-; RV64XTHEADCONDMOV-NEXT:    and a0, a0, a2
+; RV64XTHEADCONDMOV-NEXT:    mv a0, a2
+; RV64XTHEADCONDMOV-NEXT:    andi a1, a1, 1
+; RV64XTHEADCONDMOV-NEXT:    th.mveqz a0, zero, a1
 ; RV64XTHEADCONDMOV-NEXT:    ret
 ;
 ; RV32ZICOND-LABEL: single_bit3: