[llvm] [RISCV] Eliminate dead li after emitting VSETVLIs (PR #65934)
Yingwei Zheng via llvm-commits
llvm-commits at lists.llvm.org
Sat Nov 18 10:25:26 PST 2023
https://github.com/dtcxzyw updated https://github.com/llvm/llvm-project/pull/65934
>From 0671803cd618ca29e9c9e898bbf4b8df2f1b1fd9 Mon Sep 17 00:00:00 2001
From: Yingwei Zheng <dtcxzyw2333 at gmail.com>
Date: Sun, 19 Nov 2023 01:45:26 +0800
Subject: [PATCH] [RISCV] Eliminate dead li after emitting VSETVLIs
---
llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp | 8 +++++++
.../RISCV/rvv/fixed-vectors-masked-gather.ll | 24 -------------------
2 files changed, 8 insertions(+), 24 deletions(-)
diff --git a/llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp b/llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp
index 999ff9920716e87..5d075512937c0ec 100644
--- a/llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp
+++ b/llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp
@@ -1262,9 +1262,17 @@ void RISCVInsertVSETVLI::emitVSETVLIs(MachineBasicBlock &MBB) {
if (RISCVII::hasVLOp(TSFlags)) {
MachineOperand &VLOp = MI.getOperand(getVLOpNum(MI));
if (VLOp.isReg()) {
+ Register Reg = VLOp.getReg();
+ MachineInstr *VLOpDef = MRI->getVRegDef(Reg);
+
// Erase the AVL operand from the instruction.
VLOp.setReg(RISCV::NoRegister);
VLOp.setIsKill(false);
+
+ // If the old VLOp was only used by MI, it's dead.
+ if (VLOpDef && TII->isAddImmediate(*VLOpDef, Reg) &&
+ MRI->use_nodbg_empty(Reg))
+ VLOpDef->eraseFromParent();
}
MI.addOperand(MachineOperand::CreateReg(RISCV::VL, /*isDef*/ false,
/*isImp*/ true));
diff --git a/llvm/test/CodeGen/RISCV/rvv/fixed-vectors-masked-gather.ll b/llvm/test/CodeGen/RISCV/rvv/fixed-vectors-masked-gather.ll
index d74fd6cd3f03470..c17b1e9be0f0a24 100644
--- a/llvm/test/CodeGen/RISCV/rvv/fixed-vectors-masked-gather.ll
+++ b/llvm/test/CodeGen/RISCV/rvv/fixed-vectors-masked-gather.ll
@@ -12432,7 +12432,6 @@ define <32 x i8> @mgather_baseidx_v32i8(ptr %base, <32 x i8> %idxs, <32 x i1> %m
; RV64ZVE32F-NEXT: vmv.x.s a2, v12
; RV64ZVE32F-NEXT: add a2, a0, a2
; RV64ZVE32F-NEXT: lbu a2, 0(a2)
-; RV64ZVE32F-NEXT: li a3, 32
; RV64ZVE32F-NEXT: vmv.s.x v12, a2
; RV64ZVE32F-NEXT: vsetivli zero, 2, e8, m1, tu, ma
; RV64ZVE32F-NEXT: vslideup.vi v10, v12, 1
@@ -12470,7 +12469,6 @@ define <32 x i8> @mgather_baseidx_v32i8(ptr %base, <32 x i8> %idxs, <32 x i1> %m
; RV64ZVE32F-NEXT: vmv.x.s a2, v14
; RV64ZVE32F-NEXT: add a2, a0, a2
; RV64ZVE32F-NEXT: lbu a2, 0(a2)
-; RV64ZVE32F-NEXT: li a3, 32
; RV64ZVE32F-NEXT: vmv.s.x v14, a2
; RV64ZVE32F-NEXT: vsetivli zero, 6, e8, m1, tu, ma
; RV64ZVE32F-NEXT: vslideup.vi v10, v14, 5
@@ -12494,7 +12492,6 @@ define <32 x i8> @mgather_baseidx_v32i8(ptr %base, <32 x i8> %idxs, <32 x i1> %m
; RV64ZVE32F-NEXT: vmv.x.s a2, v13
; RV64ZVE32F-NEXT: add a2, a0, a2
; RV64ZVE32F-NEXT: lbu a2, 0(a2)
-; RV64ZVE32F-NEXT: li a3, 32
; RV64ZVE32F-NEXT: vmv.s.x v13, a2
; RV64ZVE32F-NEXT: vsetivli zero, 10, e8, m1, tu, ma
; RV64ZVE32F-NEXT: vslideup.vi v10, v13, 9
@@ -12509,7 +12506,6 @@ define <32 x i8> @mgather_baseidx_v32i8(ptr %base, <32 x i8> %idxs, <32 x i1> %m
; RV64ZVE32F-NEXT: vmv.x.s a2, v12
; RV64ZVE32F-NEXT: add a2, a0, a2
; RV64ZVE32F-NEXT: lbu a2, 0(a2)
-; RV64ZVE32F-NEXT: li a3, 32
; RV64ZVE32F-NEXT: vmv.s.x v14, a2
; RV64ZVE32F-NEXT: vsetivli zero, 11, e8, m1, tu, ma
; RV64ZVE32F-NEXT: vslideup.vi v10, v14, 10
@@ -12522,7 +12518,6 @@ define <32 x i8> @mgather_baseidx_v32i8(ptr %base, <32 x i8> %idxs, <32 x i1> %m
; RV64ZVE32F-NEXT: vmv.x.s a2, v12
; RV64ZVE32F-NEXT: add a2, a0, a2
; RV64ZVE32F-NEXT: lbu a2, 0(a2)
-; RV64ZVE32F-NEXT: li a3, 32
; RV64ZVE32F-NEXT: vmv.s.x v12, a2
; RV64ZVE32F-NEXT: vsetivli zero, 12, e8, m1, tu, ma
; RV64ZVE32F-NEXT: vslideup.vi v10, v12, 11
@@ -12535,7 +12530,6 @@ define <32 x i8> @mgather_baseidx_v32i8(ptr %base, <32 x i8> %idxs, <32 x i1> %m
; RV64ZVE32F-NEXT: vmv.x.s a2, v13
; RV64ZVE32F-NEXT: add a2, a0, a2
; RV64ZVE32F-NEXT: lbu a2, 0(a2)
-; RV64ZVE32F-NEXT: li a3, 32
; RV64ZVE32F-NEXT: vmv.s.x v9, a2
; RV64ZVE32F-NEXT: vsetivli zero, 13, e8, m1, tu, ma
; RV64ZVE32F-NEXT: vslideup.vi v10, v9, 12
@@ -12548,7 +12542,6 @@ define <32 x i8> @mgather_baseidx_v32i8(ptr %base, <32 x i8> %idxs, <32 x i1> %m
; RV64ZVE32F-NEXT: vmv.x.s a2, v9
; RV64ZVE32F-NEXT: add a2, a0, a2
; RV64ZVE32F-NEXT: lbu a2, 0(a2)
-; RV64ZVE32F-NEXT: li a3, 32
; RV64ZVE32F-NEXT: vmv.s.x v9, a2
; RV64ZVE32F-NEXT: vsetivli zero, 14, e8, m1, tu, ma
; RV64ZVE32F-NEXT: vslideup.vi v10, v9, 13
@@ -12572,7 +12565,6 @@ define <32 x i8> @mgather_baseidx_v32i8(ptr %base, <32 x i8> %idxs, <32 x i1> %m
; RV64ZVE32F-NEXT: vmv.x.s a2, v9
; RV64ZVE32F-NEXT: add a2, a0, a2
; RV64ZVE32F-NEXT: lbu a2, 0(a2)
-; RV64ZVE32F-NEXT: li a3, 32
; RV64ZVE32F-NEXT: vmv.s.x v12, a2
; RV64ZVE32F-NEXT: vsetivli zero, 18, e8, m2, tu, ma
; RV64ZVE32F-NEXT: vslideup.vi v10, v12, 17
@@ -12610,7 +12602,6 @@ define <32 x i8> @mgather_baseidx_v32i8(ptr %base, <32 x i8> %idxs, <32 x i1> %m
; RV64ZVE32F-NEXT: vmv.x.s a2, v12
; RV64ZVE32F-NEXT: add a2, a0, a2
; RV64ZVE32F-NEXT: lbu a2, 0(a2)
-; RV64ZVE32F-NEXT: li a3, 32
; RV64ZVE32F-NEXT: vmv.s.x v12, a2
; RV64ZVE32F-NEXT: vsetivli zero, 22, e8, m2, tu, ma
; RV64ZVE32F-NEXT: vslideup.vi v10, v12, 21
@@ -12634,7 +12625,6 @@ define <32 x i8> @mgather_baseidx_v32i8(ptr %base, <32 x i8> %idxs, <32 x i1> %m
; RV64ZVE32F-NEXT: vmv.x.s a2, v9
; RV64ZVE32F-NEXT: add a2, a0, a2
; RV64ZVE32F-NEXT: lbu a2, 0(a2)
-; RV64ZVE32F-NEXT: li a3, 32
; RV64ZVE32F-NEXT: vmv.s.x v12, a2
; RV64ZVE32F-NEXT: vsetivli zero, 26, e8, m2, tu, ma
; RV64ZVE32F-NEXT: vslideup.vi v10, v12, 25
@@ -12660,7 +12650,6 @@ define <32 x i8> @mgather_baseidx_v32i8(ptr %base, <32 x i8> %idxs, <32 x i1> %m
; RV64ZVE32F-NEXT: vmv.x.s a2, v8
; RV64ZVE32F-NEXT: add a2, a0, a2
; RV64ZVE32F-NEXT: lbu a2, 0(a2)
-; RV64ZVE32F-NEXT: li a3, 32
; RV64ZVE32F-NEXT: vmv.s.x v12, a2
; RV64ZVE32F-NEXT: vsetivli zero, 30, e8, m2, tu, ma
; RV64ZVE32F-NEXT: vslideup.vi v10, v12, 29
@@ -12673,7 +12662,6 @@ define <32 x i8> @mgather_baseidx_v32i8(ptr %base, <32 x i8> %idxs, <32 x i1> %m
; RV64ZVE32F-NEXT: vmv.x.s a2, v8
; RV64ZVE32F-NEXT: add a2, a0, a2
; RV64ZVE32F-NEXT: lbu a2, 0(a2)
-; RV64ZVE32F-NEXT: li a3, 32
; RV64ZVE32F-NEXT: vmv.s.x v12, a2
; RV64ZVE32F-NEXT: vsetivli zero, 31, e8, m2, tu, ma
; RV64ZVE32F-NEXT: vslideup.vi v10, v12, 30
@@ -12698,7 +12686,6 @@ define <32 x i8> @mgather_baseidx_v32i8(ptr %base, <32 x i8> %idxs, <32 x i1> %m
; RV64ZVE32F-NEXT: vmv.x.s a2, v12
; RV64ZVE32F-NEXT: add a2, a0, a2
; RV64ZVE32F-NEXT: lbu a2, 0(a2)
-; RV64ZVE32F-NEXT: li a3, 32
; RV64ZVE32F-NEXT: vmv.s.x v14, a2
; RV64ZVE32F-NEXT: vsetivli zero, 3, e8, m1, tu, ma
; RV64ZVE32F-NEXT: vslideup.vi v10, v14, 2
@@ -12710,7 +12697,6 @@ define <32 x i8> @mgather_baseidx_v32i8(ptr %base, <32 x i8> %idxs, <32 x i1> %m
; RV64ZVE32F-NEXT: vmv.x.s a2, v12
; RV64ZVE32F-NEXT: add a2, a0, a2
; RV64ZVE32F-NEXT: lbu a2, 0(a2)
-; RV64ZVE32F-NEXT: li a3, 32
; RV64ZVE32F-NEXT: vmv.s.x v12, a2
; RV64ZVE32F-NEXT: vsetivli zero, 4, e8, m1, tu, ma
; RV64ZVE32F-NEXT: vslideup.vi v10, v12, 3
@@ -12721,7 +12707,6 @@ define <32 x i8> @mgather_baseidx_v32i8(ptr %base, <32 x i8> %idxs, <32 x i1> %m
; RV64ZVE32F-NEXT: vmv.x.s a2, v13
; RV64ZVE32F-NEXT: add a2, a0, a2
; RV64ZVE32F-NEXT: lbu a2, 0(a2)
-; RV64ZVE32F-NEXT: li a3, 32
; RV64ZVE32F-NEXT: vmv.s.x v14, a2
; RV64ZVE32F-NEXT: vsetivli zero, 7, e8, m1, tu, ma
; RV64ZVE32F-NEXT: vslideup.vi v10, v14, 6
@@ -12733,7 +12718,6 @@ define <32 x i8> @mgather_baseidx_v32i8(ptr %base, <32 x i8> %idxs, <32 x i1> %m
; RV64ZVE32F-NEXT: vmv.x.s a2, v13
; RV64ZVE32F-NEXT: add a2, a0, a2
; RV64ZVE32F-NEXT: lbu a2, 0(a2)
-; RV64ZVE32F-NEXT: li a3, 32
; RV64ZVE32F-NEXT: vmv.s.x v13, a2
; RV64ZVE32F-NEXT: vsetivli zero, 8, e8, m1, tu, ma
; RV64ZVE32F-NEXT: vslideup.vi v10, v13, 7
@@ -12756,7 +12740,6 @@ define <32 x i8> @mgather_baseidx_v32i8(ptr %base, <32 x i8> %idxs, <32 x i1> %m
; RV64ZVE32F-NEXT: vmv.x.s a2, v9
; RV64ZVE32F-NEXT: add a2, a0, a2
; RV64ZVE32F-NEXT: lbu a2, 0(a2)
-; RV64ZVE32F-NEXT: li a3, 32
; RV64ZVE32F-NEXT: vmv.s.x v12, a2
; RV64ZVE32F-NEXT: vsetivli zero, 15, e8, m1, tu, ma
; RV64ZVE32F-NEXT: vslideup.vi v10, v12, 14
@@ -12768,7 +12751,6 @@ define <32 x i8> @mgather_baseidx_v32i8(ptr %base, <32 x i8> %idxs, <32 x i1> %m
; RV64ZVE32F-NEXT: vmv.x.s a2, v9
; RV64ZVE32F-NEXT: add a2, a0, a2
; RV64ZVE32F-NEXT: lbu a2, 0(a2)
-; RV64ZVE32F-NEXT: li a3, 32
; RV64ZVE32F-NEXT: vmv.s.x v9, a2
; RV64ZVE32F-NEXT: vsetivli zero, 16, e8, m1, tu, ma
; RV64ZVE32F-NEXT: vslideup.vi v10, v9, 15
@@ -12791,7 +12773,6 @@ define <32 x i8> @mgather_baseidx_v32i8(ptr %base, <32 x i8> %idxs, <32 x i1> %m
; RV64ZVE32F-NEXT: vmv.x.s a2, v12
; RV64ZVE32F-NEXT: add a2, a0, a2
; RV64ZVE32F-NEXT: lbu a2, 0(a2)
-; RV64ZVE32F-NEXT: li a3, 32
; RV64ZVE32F-NEXT: vmv.s.x v14, a2
; RV64ZVE32F-NEXT: vsetivli zero, 19, e8, m2, tu, ma
; RV64ZVE32F-NEXT: vslideup.vi v10, v14, 18
@@ -12803,7 +12784,6 @@ define <32 x i8> @mgather_baseidx_v32i8(ptr %base, <32 x i8> %idxs, <32 x i1> %m
; RV64ZVE32F-NEXT: vmv.x.s a2, v12
; RV64ZVE32F-NEXT: add a2, a0, a2
; RV64ZVE32F-NEXT: lbu a2, 0(a2)
-; RV64ZVE32F-NEXT: li a3, 32
; RV64ZVE32F-NEXT: vmv.s.x v12, a2
; RV64ZVE32F-NEXT: vsetivli zero, 20, e8, m2, tu, ma
; RV64ZVE32F-NEXT: vslideup.vi v10, v12, 19
@@ -12814,7 +12794,6 @@ define <32 x i8> @mgather_baseidx_v32i8(ptr %base, <32 x i8> %idxs, <32 x i1> %m
; RV64ZVE32F-NEXT: vmv.x.s a2, v9
; RV64ZVE32F-NEXT: add a2, a0, a2
; RV64ZVE32F-NEXT: lbu a2, 0(a2)
-; RV64ZVE32F-NEXT: li a3, 32
; RV64ZVE32F-NEXT: vmv.s.x v12, a2
; RV64ZVE32F-NEXT: vsetivli zero, 23, e8, m2, tu, ma
; RV64ZVE32F-NEXT: vslideup.vi v10, v12, 22
@@ -12826,7 +12805,6 @@ define <32 x i8> @mgather_baseidx_v32i8(ptr %base, <32 x i8> %idxs, <32 x i1> %m
; RV64ZVE32F-NEXT: vmv.x.s a2, v9
; RV64ZVE32F-NEXT: add a2, a0, a2
; RV64ZVE32F-NEXT: lbu a2, 0(a2)
-; RV64ZVE32F-NEXT: li a3, 32
; RV64ZVE32F-NEXT: vmv.s.x v12, a2
; RV64ZVE32F-NEXT: vsetivli zero, 24, e8, m2, tu, ma
; RV64ZVE32F-NEXT: vslideup.vi v10, v12, 23
@@ -12849,7 +12827,6 @@ define <32 x i8> @mgather_baseidx_v32i8(ptr %base, <32 x i8> %idxs, <32 x i1> %m
; RV64ZVE32F-NEXT: vmv.x.s a2, v8
; RV64ZVE32F-NEXT: add a2, a0, a2
; RV64ZVE32F-NEXT: lbu a2, 0(a2)
-; RV64ZVE32F-NEXT: li a3, 32
; RV64ZVE32F-NEXT: vmv.s.x v12, a2
; RV64ZVE32F-NEXT: vsetivli zero, 27, e8, m2, tu, ma
; RV64ZVE32F-NEXT: vslideup.vi v10, v12, 26
@@ -12861,7 +12838,6 @@ define <32 x i8> @mgather_baseidx_v32i8(ptr %base, <32 x i8> %idxs, <32 x i1> %m
; RV64ZVE32F-NEXT: vmv.x.s a2, v8
; RV64ZVE32F-NEXT: add a2, a0, a2
; RV64ZVE32F-NEXT: lbu a2, 0(a2)
-; RV64ZVE32F-NEXT: li a3, 32
; RV64ZVE32F-NEXT: vmv.s.x v12, a2
; RV64ZVE32F-NEXT: vsetivli zero, 28, e8, m2, tu, ma
; RV64ZVE32F-NEXT: vslideup.vi v10, v12, 27
More information about the llvm-commits
mailing list