[llvm] [RISCV] Add Zilx loads to getJumpTableIndex. (PR #227557)
Craig Topper via llvm-commits
llvm-commits at lists.llvm.org
Tue Sep 29 22:03:51 PDT 2026
https://github.com/topperc created https://github.com/llvm/llvm-project/pull/227557
None
>From 57ea9fb1c6ae63cd8f3bf26667a9ddbef8605c7b Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper at sifive.com>
Date: Tue, 29 Sep 2026 21:39:59 -0700
Subject: [PATCH 1/2] Pre-commit test
---
.../machine-sink-jumptable-edge-split.ll | 87 +++++++++++++++++++
1 file changed, 87 insertions(+)
diff --git a/llvm/test/CodeGen/RISCV/machine-sink-jumptable-edge-split.ll b/llvm/test/CodeGen/RISCV/machine-sink-jumptable-edge-split.ll
index b6c98e469940d..795b6b2a4e5d8 100644
--- a/llvm/test/CodeGen/RISCV/machine-sink-jumptable-edge-split.ll
+++ b/llvm/test/CodeGen/RISCV/machine-sink-jumptable-edge-split.ll
@@ -6,6 +6,7 @@
; RUN: llc -mtriple=riscv64 -code-model=small -mattr=+zba -O3 < %s | FileCheck %s --check-prefixes=RV64I-SMALL,CHECK
; RUN: llc -mtriple=riscv64 -code-model=medium -mattr=+zba -O3 < %s | FileCheck %s --check-prefix=RV64I-MEDIUM
; RUN: llc -mtriple=riscv64 -relocation-model=pic -mattr=+zba -O3 < %s | FileCheck %s --check-prefix=RV64I-PIC
+; RUN: llc -mtriple=riscv64 -code-model=small -mattr=+experimental-zilx -O3 < %s | FileCheck %s --check-prefixes=RV64ZILX-SMALL,CHECK
declare void @use(i32)
@@ -637,6 +638,92 @@ define void @sink_through_jt(ptr %p) {
; RV64I-PIC-NEXT: # in Loop: Header=BB0_3 Depth=1
; RV64I-PIC-NEXT: li a0, 107
; RV64I-PIC-NEXT: j .LBB0_2
+;
+; RV64ZILX-SMALL-LABEL: sink_through_jt:
+; RV64ZILX-SMALL: # %bb.0: # %entry
+; RV64ZILX-SMALL-NEXT: addi sp, sp, -32
+; RV64ZILX-SMALL-NEXT: .cfi_def_cfa_offset 32
+; RV64ZILX-SMALL-NEXT: sd ra, 24(sp) # 8-byte Folded Spill
+; RV64ZILX-SMALL-NEXT: sd s0, 16(sp) # 8-byte Folded Spill
+; RV64ZILX-SMALL-NEXT: sd s1, 8(sp) # 8-byte Folded Spill
+; RV64ZILX-SMALL-NEXT: sd s2, 0(sp) # 8-byte Folded Spill
+; RV64ZILX-SMALL-NEXT: .cfi_offset ra, -8
+; RV64ZILX-SMALL-NEXT: .cfi_offset s0, -16
+; RV64ZILX-SMALL-NEXT: .cfi_offset s1, -24
+; RV64ZILX-SMALL-NEXT: .cfi_offset s2, -32
+; RV64ZILX-SMALL-NEXT: li s0, 12
+; RV64ZILX-SMALL-NEXT: addi s1, a0, 1
+; RV64ZILX-SMALL-NEXT: lui s2, %hi(.LJTI0_0)
+; RV64ZILX-SMALL-NEXT: addi s2, s2, %lo(.LJTI0_0)
+; RV64ZILX-SMALL-NEXT: j .LBB0_3
+; RV64ZILX-SMALL-NEXT: .LBB0_1: # %c10
+; RV64ZILX-SMALL-NEXT: # in Loop: Header=BB0_3 Depth=1
+; RV64ZILX-SMALL-NEXT: li a0, 110
+; RV64ZILX-SMALL-NEXT: .LBB0_2: # %m
+; RV64ZILX-SMALL-NEXT: # in Loop: Header=BB0_3 Depth=1
+; RV64ZILX-SMALL-NEXT: call use
+; RV64ZILX-SMALL-NEXT: addi s1, s1, 1
+; RV64ZILX-SMALL-NEXT: .LBB0_3: # %disp
+; RV64ZILX-SMALL-NEXT: # =>This Inner Loop Header: Depth=1
+; RV64ZILX-SMALL-NEXT: lbu a0, -1(s1)
+; RV64ZILX-SMALL-NEXT: addi a0, a0, -1
+; RV64ZILX-SMALL-NEXT: bltu s0, a0, .LBB0_13
+; RV64ZILX-SMALL-NEXT: # %bb.4: # %disp
+; RV64ZILX-SMALL-NEXT: # in Loop: Header=BB0_3 Depth=1
+; RV64ZILX-SMALL-NEXT: lw a1, 0(s1)
+; RV64ZILX-SMALL-NEXT: lxsw a2, (s2), a0
+; RV64ZILX-SMALL-NEXT: addiw a0, a1, 7
+; RV64ZILX-SMALL-NEXT: jr a2
+; RV64ZILX-SMALL-NEXT: .LBB0_5: # %other
+; RV64ZILX-SMALL-NEXT: # in Loop: Header=BB0_3 Depth=1
+; RV64ZILX-SMALL-NEXT: li a0, 55
+; RV64ZILX-SMALL-NEXT: call use
+; RV64ZILX-SMALL-NEXT: li a0, 0
+; RV64ZILX-SMALL-NEXT: j .LBB0_2
+; RV64ZILX-SMALL-NEXT: .LBB0_6: # %c3
+; RV64ZILX-SMALL-NEXT: # in Loop: Header=BB0_3 Depth=1
+; RV64ZILX-SMALL-NEXT: li a0, 103
+; RV64ZILX-SMALL-NEXT: j .LBB0_2
+; RV64ZILX-SMALL-NEXT: .LBB0_7: # %c11
+; RV64ZILX-SMALL-NEXT: # in Loop: Header=BB0_3 Depth=1
+; RV64ZILX-SMALL-NEXT: li a0, 111
+; RV64ZILX-SMALL-NEXT: j .LBB0_2
+; RV64ZILX-SMALL-NEXT: .LBB0_8: # %c8
+; RV64ZILX-SMALL-NEXT: # in Loop: Header=BB0_3 Depth=1
+; RV64ZILX-SMALL-NEXT: li a0, 108
+; RV64ZILX-SMALL-NEXT: j .LBB0_2
+; RV64ZILX-SMALL-NEXT: .LBB0_9: # %c1
+; RV64ZILX-SMALL-NEXT: # in Loop: Header=BB0_3 Depth=1
+; RV64ZILX-SMALL-NEXT: li a0, 101
+; RV64ZILX-SMALL-NEXT: j .LBB0_2
+; RV64ZILX-SMALL-NEXT: .LBB0_10: # %c2
+; RV64ZILX-SMALL-NEXT: # in Loop: Header=BB0_3 Depth=1
+; RV64ZILX-SMALL-NEXT: li a0, 102
+; RV64ZILX-SMALL-NEXT: j .LBB0_2
+; RV64ZILX-SMALL-NEXT: .LBB0_11: # %c6
+; RV64ZILX-SMALL-NEXT: # in Loop: Header=BB0_3 Depth=1
+; RV64ZILX-SMALL-NEXT: li a0, 106
+; RV64ZILX-SMALL-NEXT: j .LBB0_2
+; RV64ZILX-SMALL-NEXT: .LBB0_12: # %c4
+; RV64ZILX-SMALL-NEXT: # in Loop: Header=BB0_3 Depth=1
+; RV64ZILX-SMALL-NEXT: li a0, 104
+; RV64ZILX-SMALL-NEXT: j .LBB0_2
+; RV64ZILX-SMALL-NEXT: .LBB0_13: # %c0
+; RV64ZILX-SMALL-NEXT: # in Loop: Header=BB0_3 Depth=1
+; RV64ZILX-SMALL-NEXT: li a0, 100
+; RV64ZILX-SMALL-NEXT: j .LBB0_2
+; RV64ZILX-SMALL-NEXT: .LBB0_14: # %c5
+; RV64ZILX-SMALL-NEXT: # in Loop: Header=BB0_3 Depth=1
+; RV64ZILX-SMALL-NEXT: li a0, 105
+; RV64ZILX-SMALL-NEXT: j .LBB0_2
+; RV64ZILX-SMALL-NEXT: .LBB0_15: # %c9
+; RV64ZILX-SMALL-NEXT: # in Loop: Header=BB0_3 Depth=1
+; RV64ZILX-SMALL-NEXT: li a0, 109
+; RV64ZILX-SMALL-NEXT: j .LBB0_2
+; RV64ZILX-SMALL-NEXT: .LBB0_16: # %c7
+; RV64ZILX-SMALL-NEXT: # in Loop: Header=BB0_3 Depth=1
+; RV64ZILX-SMALL-NEXT: li a0, 107
+; RV64ZILX-SMALL-NEXT: j .LBB0_2
entry:
br label %disp
>From f0a978970ad2e7f3e9c3171a4939b9a7bcd0a80f Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper at sifive.com>
Date: Tue, 29 Sep 2026 22:01:38 -0700
Subject: [PATCH 2/2] [RISCV] Add Zilx loads to getJumpTableIndex.
---
llvm/lib/Target/RISCV/RISCVInstrInfo.cpp | 11 ++++++-
.../machine-sink-jumptable-edge-split.ll | 32 ++++++++++---------
2 files changed, 27 insertions(+), 16 deletions(-)
diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp b/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
index e7aaeb0ac9e97..691884f6b8c58 100644
--- a/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
@@ -1908,7 +1908,6 @@ int RISCVInstrInfo::getJumpTableIndex(const MachineInstr &MI) const {
case RISCV::LW:
case RISCV::LWU:
case RISCV::LD:
- // TODO: Zilx
if (!isJumpTableLoad(*Def))
return -1;
@@ -1916,6 +1915,16 @@ int RISCVInstrInfo::getJumpTableIndex(const MachineInstr &MI) const {
if (JTI >= 0)
return JTI;
break;
+ case RISCV::LXSW:
+ case RISCV::LXWU:
+ case RISCV::LXSD:
+ if (!isJumpTableLoad(*Def))
+ return -1;
+
+ JTI = getJumpTableIndexFromBase(MRI, Def->getOperand(1).getReg());
+ if (JTI >= 0)
+ return JTI;
+ break;
case RISCV::ADD:
JTI = getJumpTableIndexFromBase(MRI, Def->getOperand(1).getReg());
if (JTI >= 0)
diff --git a/llvm/test/CodeGen/RISCV/machine-sink-jumptable-edge-split.ll b/llvm/test/CodeGen/RISCV/machine-sink-jumptable-edge-split.ll
index 795b6b2a4e5d8..3606492b82792 100644
--- a/llvm/test/CodeGen/RISCV/machine-sink-jumptable-edge-split.ll
+++ b/llvm/test/CodeGen/RISCV/machine-sink-jumptable-edge-split.ll
@@ -667,18 +667,14 @@ define void @sink_through_jt(ptr %p) {
; RV64ZILX-SMALL-NEXT: # =>This Inner Loop Header: Depth=1
; RV64ZILX-SMALL-NEXT: lbu a0, -1(s1)
; RV64ZILX-SMALL-NEXT: addi a0, a0, -1
-; RV64ZILX-SMALL-NEXT: bltu s0, a0, .LBB0_13
+; RV64ZILX-SMALL-NEXT: bltu s0, a0, .LBB0_14
; RV64ZILX-SMALL-NEXT: # %bb.4: # %disp
; RV64ZILX-SMALL-NEXT: # in Loop: Header=BB0_3 Depth=1
-; RV64ZILX-SMALL-NEXT: lw a1, 0(s1)
-; RV64ZILX-SMALL-NEXT: lxsw a2, (s2), a0
-; RV64ZILX-SMALL-NEXT: addiw a0, a1, 7
-; RV64ZILX-SMALL-NEXT: jr a2
-; RV64ZILX-SMALL-NEXT: .LBB0_5: # %other
-; RV64ZILX-SMALL-NEXT: # in Loop: Header=BB0_3 Depth=1
-; RV64ZILX-SMALL-NEXT: li a0, 55
-; RV64ZILX-SMALL-NEXT: call use
-; RV64ZILX-SMALL-NEXT: li a0, 0
+; RV64ZILX-SMALL-NEXT: lxsw a0, (s2), a0
+; RV64ZILX-SMALL-NEXT: jr a0
+; RV64ZILX-SMALL-NEXT: .LBB0_5: # in Loop: Header=BB0_3 Depth=1
+; RV64ZILX-SMALL-NEXT: lw a0, 0(s1)
+; RV64ZILX-SMALL-NEXT: addiw a0, a0, 7
; RV64ZILX-SMALL-NEXT: j .LBB0_2
; RV64ZILX-SMALL-NEXT: .LBB0_6: # %c3
; RV64ZILX-SMALL-NEXT: # in Loop: Header=BB0_3 Depth=1
@@ -704,23 +700,29 @@ define void @sink_through_jt(ptr %p) {
; RV64ZILX-SMALL-NEXT: # in Loop: Header=BB0_3 Depth=1
; RV64ZILX-SMALL-NEXT: li a0, 106
; RV64ZILX-SMALL-NEXT: j .LBB0_2
-; RV64ZILX-SMALL-NEXT: .LBB0_12: # %c4
+; RV64ZILX-SMALL-NEXT: .LBB0_12: # %other
+; RV64ZILX-SMALL-NEXT: # in Loop: Header=BB0_3 Depth=1
+; RV64ZILX-SMALL-NEXT: li a0, 55
+; RV64ZILX-SMALL-NEXT: call use
+; RV64ZILX-SMALL-NEXT: li a0, 0
+; RV64ZILX-SMALL-NEXT: j .LBB0_2
+; RV64ZILX-SMALL-NEXT: .LBB0_13: # %c4
; RV64ZILX-SMALL-NEXT: # in Loop: Header=BB0_3 Depth=1
; RV64ZILX-SMALL-NEXT: li a0, 104
; RV64ZILX-SMALL-NEXT: j .LBB0_2
-; RV64ZILX-SMALL-NEXT: .LBB0_13: # %c0
+; RV64ZILX-SMALL-NEXT: .LBB0_14: # %c0
; RV64ZILX-SMALL-NEXT: # in Loop: Header=BB0_3 Depth=1
; RV64ZILX-SMALL-NEXT: li a0, 100
; RV64ZILX-SMALL-NEXT: j .LBB0_2
-; RV64ZILX-SMALL-NEXT: .LBB0_14: # %c5
+; RV64ZILX-SMALL-NEXT: .LBB0_15: # %c5
; RV64ZILX-SMALL-NEXT: # in Loop: Header=BB0_3 Depth=1
; RV64ZILX-SMALL-NEXT: li a0, 105
; RV64ZILX-SMALL-NEXT: j .LBB0_2
-; RV64ZILX-SMALL-NEXT: .LBB0_15: # %c9
+; RV64ZILX-SMALL-NEXT: .LBB0_16: # %c9
; RV64ZILX-SMALL-NEXT: # in Loop: Header=BB0_3 Depth=1
; RV64ZILX-SMALL-NEXT: li a0, 109
; RV64ZILX-SMALL-NEXT: j .LBB0_2
-; RV64ZILX-SMALL-NEXT: .LBB0_16: # %c7
+; RV64ZILX-SMALL-NEXT: .LBB0_17: # %c7
; RV64ZILX-SMALL-NEXT: # in Loop: Header=BB0_3 Depth=1
; RV64ZILX-SMALL-NEXT: li a0, 107
; RV64ZILX-SMALL-NEXT: j .LBB0_2
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