[RISC] Use hasBEXTILike in useInversedSetcc and shouldFoldSelectWithSingleBitTest. #158366
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…ingleBitTest. Add hasVendorXTHeadCondMov to shouldFoldSelectWithSingleBitTest. The optimizations in these functions is equally applicable to these. I changed the RUN line for xtheadcondmove in condops.ll to use XTHeadBs to get converage of the hasBEXTILike changes. I didn't think it was worth an additional RUN line and check prefix.
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@llvm/pr-subscribers-backend-risc-v Author: Craig Topper (topperc) ChangesAdd hasVendorXTHeadCondMov to shouldFoldSelectWithSingleBitTest. The optimizations in these functions is equally applicable to these. I changed the RUN line for xtheadcondmove in condops.ll to use XTHeadBs to get converage of the hasBEXTILike changes. I didn't think it was worth an additional RUN line and check prefix. Full diff: https://github.com/llvm/llvm-project/pull/158366.diff 2 Files Affected:
diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
index 523b857f9e6cd..c3071ad5cd697 100644
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -18950,7 +18950,7 @@ 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() &&
+ if (Subtarget.hasBEXTILike() && VT.isScalarInteger() &&
(Subtarget.hasCZEROLike() || Subtarget.hasVendorXTHeadCondMov())) {
SDValue LHS = Cond.getOperand(0);
SDValue RHS = Cond.getOperand(1);
@@ -24939,8 +24939,8 @@ RISCVTargetLowering::BuildSDIVPow2(SDNode *N, const APInt &Divisor,
bool RISCVTargetLowering::shouldFoldSelectWithSingleBitTest(
EVT VT, const APInt &AndMask) const {
- if (Subtarget.hasCZEROLike())
- return !Subtarget.hasStdExtZbs() && AndMask.ugt(1024);
+ if (Subtarget.hasCZEROLike() || Subtarget.hasVendorXTHeadCondMov())
+ return !Subtarget.hasBEXTILike() && AndMask.ugt(1024);
return TargetLowering::shouldFoldSelectWithSingleBitTest(VT, AndMask);
}
diff --git a/llvm/test/CodeGen/RISCV/condops.ll b/llvm/test/CodeGen/RISCV/condops.ll
index 4fb3dff88017c..9d95f1f5c9615 100644
--- a/llvm/test/CodeGen/RISCV/condops.ll
+++ b/llvm/test/CodeGen/RISCV/condops.ll
@@ -3,7 +3,7 @@
; RUN: llc -mtriple=riscv64 -target-abi=lp64f -mattr=+f,+zbs < %s | FileCheck %s -check-prefix=RV64I
; RUN: llc -mtriple=riscv32 -target-abi=ilp32f -mattr=+f,+zbs,+xventanacondops < %s | FileCheck %s -check-prefix=RV32XVENTANACONDOPS
; RUN: llc -mtriple=riscv64 -target-abi=lp64f -mattr=+f,+zbs,+xventanacondops < %s | FileCheck %s -check-prefix=RV64XVENTANACONDOPS
-; RUN: llc -mtriple=riscv64 -target-abi=lp64f -mattr=+f,+zbs,+xtheadcondmov < %s | FileCheck %s -check-prefix=RV64XTHEADCONDMOV
+; RUN: llc -mtriple=riscv64 -target-abi=lp64f -mattr=+f,+xtheadbs,+xtheadcondmov < %s | FileCheck %s -check-prefix=RV64XTHEADCONDMOV
; RUN: llc -mtriple=riscv32 -target-abi=ilp32f -mattr=+f,+zbs,+zicond < %s | FileCheck %s -check-prefix=RV32ZICOND
; RUN: llc -mtriple=riscv64 -target-abi=lp64f -mattr=+f,+zbs,+zicond < %s | FileCheck %s -check-prefix=RV64ZICOND
@@ -126,7 +126,7 @@ define i64 @zero_singlebit1(i64 %rs1, i64 %rs2) {
;
; RV64XTHEADCONDMOV-LABEL: zero_singlebit1:
; RV64XTHEADCONDMOV: # %bb.0:
-; RV64XTHEADCONDMOV-NEXT: bexti a1, a1, 12
+; RV64XTHEADCONDMOV-NEXT: th.tst a1, a1, 12
; RV64XTHEADCONDMOV-NEXT: th.mvnez a0, zero, a1
; RV64XTHEADCONDMOV-NEXT: ret
;
@@ -179,9 +179,8 @@ define i64 @zero_singlebit2(i64 %rs1, i64 %rs2) {
;
; RV64XTHEADCONDMOV-LABEL: zero_singlebit2:
; RV64XTHEADCONDMOV: # %bb.0:
-; RV64XTHEADCONDMOV-NEXT: slli a1, a1, 51
-; RV64XTHEADCONDMOV-NEXT: srai a1, a1, 63
-; RV64XTHEADCONDMOV-NEXT: and a0, a1, a0
+; RV64XTHEADCONDMOV-NEXT: th.tst a1, a1, 12
+; RV64XTHEADCONDMOV-NEXT: th.mveqz a0, zero, a1
; RV64XTHEADCONDMOV-NEXT: ret
;
; RV32ZICOND-LABEL: zero_singlebit2:
@@ -4297,9 +4296,8 @@ define i64 @single_bit(i64 %x) {
;
; RV64XTHEADCONDMOV-LABEL: single_bit:
; RV64XTHEADCONDMOV: # %bb.0: # %entry
-; RV64XTHEADCONDMOV-NEXT: slli a1, a0, 53
-; RV64XTHEADCONDMOV-NEXT: srai a1, a1, 63
-; RV64XTHEADCONDMOV-NEXT: and a0, a1, a0
+; RV64XTHEADCONDMOV-NEXT: andi a1, a0, 1024
+; RV64XTHEADCONDMOV-NEXT: th.mveqz a0, zero, a1
; RV64XTHEADCONDMOV-NEXT: ret
;
; RV32ZICOND-LABEL: single_bit:
@@ -4353,9 +4351,8 @@ define i64 @single_bit2(i64 %x) {
;
; RV64XTHEADCONDMOV-LABEL: single_bit2:
; RV64XTHEADCONDMOV: # %bb.0: # %entry
-; RV64XTHEADCONDMOV-NEXT: slli a1, a0, 52
-; RV64XTHEADCONDMOV-NEXT: srai a1, a1, 63
-; RV64XTHEADCONDMOV-NEXT: and a0, a1, a0
+; RV64XTHEADCONDMOV-NEXT: th.tst a1, a0, 11
+; RV64XTHEADCONDMOV-NEXT: th.mveqz a0, zero, a1
; RV64XTHEADCONDMOV-NEXT: ret
;
; RV32ZICOND-LABEL: single_bit2:
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lenary
approved these changes
Sep 12, 2025
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Add hasVendorXTHeadCondMov to shouldFoldSelectWithSingleBitTest.
The optimizations in these functions is equally applicable to these.
I changed the RUN line for xtheadcondmove in condops.ll to use XTHeadBs to get converage of the hasBEXTILike changes. I didn't think it was worth an additional RUN line and check prefix.