[llvm] [RISCV] Use LD_RV32/SD_RV32 for spills and reloads when Zilsd is enabled (PR #153595)

via llvm-commits llvm-commits at lists.llvm.org
Thu Aug 14 08:21:21 PDT 2025


llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-risc-v

Author: Sudharsan Veeravalli (svs-quic)

<details>
<summary>Changes</summary>

We are currently unilaterally using `PseudoRV32ZdinxSD/LD` for spills and reloads when the register class is `GPRPairRegClass` but we can use `LD_RV32/SD_RV32` when `Zilsd` is enabled. This isn't an issue since the `PseudoRV32ZdinxSD/LD` gets expanded into individual `LW/SW's` late but I don't think it's right to use it even when `Zdinx` is not enabled.

---
Full diff: https://github.com/llvm/llvm-project/pull/153595.diff


2 Files Affected:

- (modified) llvm/lib/Target/RISCV/RISCVInstrInfo.cpp (+12-2) 
- (modified) llvm/test/CodeGen/RISCV/zdinx-spill.ll (+73-36) 


``````````diff
diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp b/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
index 085064eee896a..cd75f6709e1e8 100644
--- a/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
@@ -658,7 +658,12 @@ void RISCVInstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
   } else if (RISCV::GPRF32RegClass.hasSubClassEq(RC)) {
     Opcode = RISCV::SW_INX;
   } else if (RISCV::GPRPairRegClass.hasSubClassEq(RC)) {
-    Opcode = RISCV::PseudoRV32ZdinxSD;
+    if (STI.hasStdExtZilsd() && !STI.is64Bit()) {
+      Opcode = RISCV::SD_RV32;
+    } else {
+      assert(STI.hasStdExtZdinx() && !STI.is64Bit());
+      Opcode = RISCV::PseudoRV32ZdinxSD;
+    }
   } else if (RISCV::FPR16RegClass.hasSubClassEq(RC)) {
     Opcode = RISCV::FSH;
   } else if (RISCV::FPR32RegClass.hasSubClassEq(RC)) {
@@ -742,7 +747,12 @@ void RISCVInstrInfo::loadRegFromStackSlot(
   } else if (RISCV::GPRF32RegClass.hasSubClassEq(RC)) {
     Opcode = RISCV::LW_INX;
   } else if (RISCV::GPRPairRegClass.hasSubClassEq(RC)) {
-    Opcode = RISCV::PseudoRV32ZdinxLD;
+    if (STI.hasStdExtZilsd() && !STI.is64Bit()) {
+      Opcode = RISCV::LD_RV32;
+    } else {
+      assert(STI.hasStdExtZdinx() && !STI.is64Bit());
+      Opcode = RISCV::PseudoRV32ZdinxLD;
+    }
   } else if (RISCV::FPR16RegClass.hasSubClassEq(RC)) {
     Opcode = RISCV::FLH;
   } else if (RISCV::FPR32RegClass.hasSubClassEq(RC)) {
diff --git a/llvm/test/CodeGen/RISCV/zdinx-spill.ll b/llvm/test/CodeGen/RISCV/zdinx-spill.ll
index 6f206fe571c17..526392b0280cb 100644
--- a/llvm/test/CodeGen/RISCV/zdinx-spill.ll
+++ b/llvm/test/CodeGen/RISCV/zdinx-spill.ll
@@ -1,44 +1,81 @@
 ; NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 5
-; RUN: llc < %s -mtriple=riscv32 -mattr=+zdinx -verify-machineinstrs -stop-after=prologepilog | FileCheck %s
+; RUN: llc < %s -mtriple=riscv32 -mattr=+zdinx -verify-machineinstrs -stop-after=prologepilog | FileCheck %s -check-prefix=ZDINX
+; RUN: llc < %s -mtriple=riscv32 -mattr=+zdinx,+zilsd -verify-machineinstrs -stop-after=prologepilog | FileCheck %s -check-prefix=ZDINX-ZILSD
 
 declare void @bar()
 
 define double @foo(double %x) nounwind {
-  ; CHECK-LABEL: name: foo
-  ; CHECK: bb.0 (%ir-block.0):
-  ; CHECK-NEXT:   liveins: $x10, $x11, $x8, $x9, $x18, $x19, $x20, $x21, $x22, $x23, $x24, $x25, $x26, $x27
-  ; CHECK-NEXT: {{  $}}
-  ; CHECK-NEXT:   $x2 = frame-setup ADDI $x2, -64
-  ; CHECK-NEXT:   frame-setup SW killed $x8, $x2, 60 :: (store (s32) into %stack.1)
-  ; CHECK-NEXT:   frame-setup SW killed $x9, $x2, 56 :: (store (s32) into %stack.2)
-  ; CHECK-NEXT:   frame-setup SW killed $x18, $x2, 52 :: (store (s32) into %stack.3)
-  ; CHECK-NEXT:   frame-setup SW killed $x19, $x2, 48 :: (store (s32) into %stack.4)
-  ; CHECK-NEXT:   frame-setup SW killed $x20, $x2, 44 :: (store (s32) into %stack.5)
-  ; CHECK-NEXT:   frame-setup SW killed $x21, $x2, 40 :: (store (s32) into %stack.6)
-  ; CHECK-NEXT:   frame-setup SW killed $x22, $x2, 36 :: (store (s32) into %stack.7)
-  ; CHECK-NEXT:   frame-setup SW killed $x23, $x2, 32 :: (store (s32) into %stack.8)
-  ; CHECK-NEXT:   frame-setup SW killed $x24, $x2, 28 :: (store (s32) into %stack.9)
-  ; CHECK-NEXT:   frame-setup SW killed $x25, $x2, 24 :: (store (s32) into %stack.10)
-  ; CHECK-NEXT:   frame-setup SW killed $x26, $x2, 20 :: (store (s32) into %stack.11)
-  ; CHECK-NEXT:   frame-setup SW killed $x27, $x2, 16 :: (store (s32) into %stack.12)
-  ; CHECK-NEXT:   renamable $x10_x11 = nofpexcept FADD_D_IN32X killed renamable $x10_x11, renamable $x10_x11, 7, implicit $frm
-  ; CHECK-NEXT:   PseudoRV32ZdinxSD killed renamable $x10_x11, $x2, 8 :: (store (s64) into %stack.0, align 4)
-  ; CHECK-NEXT:   INLINEASM &"", 1 /* sideeffect attdialect */, 12 /* clobber */, implicit-def dead early-clobber $x6, 12 /* clobber */, implicit-def dead early-clobber $x7, 12 /* clobber */, implicit-def dead early-clobber $x8, 12 /* clobber */, implicit-def dead early-clobber $x9, 12 /* clobber */, implicit-def dead early-clobber $x10, 12 /* clobber */, implicit-def dead early-clobber $x11, 12 /* clobber */, implicit-def dead early-clobber $x12, 12 /* clobber */, implicit-def dead early-clobber $x13, 12 /* clobber */, implicit-def dead early-clobber $x14, 12 /* clobber */, implicit-def dead early-clobber $x15, 12 /* clobber */, implicit-def dead early-clobber $x16, 12 /* clobber */, implicit-def dead early-clobber $x17, 12 /* clobber */, implicit-def dead early-clobber $x18, 12 /* clobber */, implicit-def dead early-clobber $x19, 12 /* clobber */, implicit-def dead early-clobber $x20, 12 /* clobber */, implicit-def dead early-clobber $x21, 12 /* clobber */, implicit-def dead early-clobber $x22, 12 /* clobber */, implicit-def dead early-clobber $x23, 12 /* clobber */, implicit-def dead early-clobber $x24, 12 /* clobber */, implicit-def dead early-clobber $x25, 12 /* clobber */, implicit-def dead early-clobber $x26, 12 /* clobber */, implicit-def dead early-clobber $x27, 12 /* clobber */, implicit-def dead early-clobber $x28, 12 /* clobber */, implicit-def dead early-clobber $x29, 12 /* clobber */, implicit-def dead early-clobber $x31
-  ; CHECK-NEXT:   renamable $x10_x11 = PseudoRV32ZdinxLD $x2, 8 :: (load (s64) from %stack.0, align 4)
-  ; CHECK-NEXT:   $x8 = frame-destroy LW $x2, 60 :: (load (s32) from %stack.1)
-  ; CHECK-NEXT:   $x9 = frame-destroy LW $x2, 56 :: (load (s32) from %stack.2)
-  ; CHECK-NEXT:   $x18 = frame-destroy LW $x2, 52 :: (load (s32) from %stack.3)
-  ; CHECK-NEXT:   $x19 = frame-destroy LW $x2, 48 :: (load (s32) from %stack.4)
-  ; CHECK-NEXT:   $x20 = frame-destroy LW $x2, 44 :: (load (s32) from %stack.5)
-  ; CHECK-NEXT:   $x21 = frame-destroy LW $x2, 40 :: (load (s32) from %stack.6)
-  ; CHECK-NEXT:   $x22 = frame-destroy LW $x2, 36 :: (load (s32) from %stack.7)
-  ; CHECK-NEXT:   $x23 = frame-destroy LW $x2, 32 :: (load (s32) from %stack.8)
-  ; CHECK-NEXT:   $x24 = frame-destroy LW $x2, 28 :: (load (s32) from %stack.9)
-  ; CHECK-NEXT:   $x25 = frame-destroy LW $x2, 24 :: (load (s32) from %stack.10)
-  ; CHECK-NEXT:   $x26 = frame-destroy LW $x2, 20 :: (load (s32) from %stack.11)
-  ; CHECK-NEXT:   $x27 = frame-destroy LW $x2, 16 :: (load (s32) from %stack.12)
-  ; CHECK-NEXT:   $x2 = frame-destroy ADDI $x2, 64
-  ; CHECK-NEXT:   PseudoRET implicit $x10, implicit $x11
+  ; ZDINX-LABEL: name: foo
+  ; ZDINX: bb.0 (%ir-block.0):
+  ; ZDINX-NEXT:   liveins: $x10, $x11, $x8, $x9, $x18, $x19, $x20, $x21, $x22, $x23, $x24, $x25, $x26, $x27
+  ; ZDINX-NEXT: {{  $}}
+  ; ZDINX-NEXT:   $x2 = frame-setup ADDI $x2, -64
+  ; ZDINX-NEXT:   frame-setup SW killed $x8, $x2, 60 :: (store (s32) into %stack.1)
+  ; ZDINX-NEXT:   frame-setup SW killed $x9, $x2, 56 :: (store (s32) into %stack.2)
+  ; ZDINX-NEXT:   frame-setup SW killed $x18, $x2, 52 :: (store (s32) into %stack.3)
+  ; ZDINX-NEXT:   frame-setup SW killed $x19, $x2, 48 :: (store (s32) into %stack.4)
+  ; ZDINX-NEXT:   frame-setup SW killed $x20, $x2, 44 :: (store (s32) into %stack.5)
+  ; ZDINX-NEXT:   frame-setup SW killed $x21, $x2, 40 :: (store (s32) into %stack.6)
+  ; ZDINX-NEXT:   frame-setup SW killed $x22, $x2, 36 :: (store (s32) into %stack.7)
+  ; ZDINX-NEXT:   frame-setup SW killed $x23, $x2, 32 :: (store (s32) into %stack.8)
+  ; ZDINX-NEXT:   frame-setup SW killed $x24, $x2, 28 :: (store (s32) into %stack.9)
+  ; ZDINX-NEXT:   frame-setup SW killed $x25, $x2, 24 :: (store (s32) into %stack.10)
+  ; ZDINX-NEXT:   frame-setup SW killed $x26, $x2, 20 :: (store (s32) into %stack.11)
+  ; ZDINX-NEXT:   frame-setup SW killed $x27, $x2, 16 :: (store (s32) into %stack.12)
+  ; ZDINX-NEXT:   renamable $x10_x11 = nofpexcept FADD_D_IN32X killed renamable $x10_x11, renamable $x10_x11, 7, implicit $frm
+  ; ZDINX-NEXT:   PseudoRV32ZdinxSD killed renamable $x10_x11, $x2, 8 :: (store (s64) into %stack.0, align 4)
+  ; ZDINX-NEXT:   INLINEASM &"", 1 /* sideeffect attdialect */, 12 /* clobber */, implicit-def dead early-clobber $x6, 12 /* clobber */, implicit-def dead early-clobber $x7, 12 /* clobber */, implicit-def dead early-clobber $x8, 12 /* clobber */, implicit-def dead early-clobber $x9, 12 /* clobber */, implicit-def dead early-clobber $x10, 12 /* clobber */, implicit-def dead early-clobber $x11, 12 /* clobber */, implicit-def dead early-clobber $x12, 12 /* clobber */, implicit-def dead early-clobber $x13, 12 /* clobber */, implicit-def dead early-clobber $x14, 12 /* clobber */, implicit-def dead early-clobber $x15, 12 /* clobber */, implicit-def dead early-clobber $x16, 12 /* clobber */, implicit-def dead early-clobber $x17, 12 /* clobber */, implicit-def dead early-clobber $x18, 12 /* clobber */, implicit-def dead early-clobber $x19, 12 /* clobber */, implicit-def dead early-clobber $x20, 12 /* clobber */, implicit-def dead early-clobber $x21, 12 /* clobber */, implicit-def dead early-clobber $x22, 12 /* clobber */, implicit-def dead early-clobber $x23, 12 /* clobber */, implicit-def dead early-clobber $x24, 12 /* clobber */, implicit-def dead early-clobber $x25, 12 /* clobber */, implicit-def dead early-clobber $x26, 12 /* clobber */, implicit-def dead early-clobber $x27, 12 /* clobber */, implicit-def dead early-clobber $x28, 12 /* clobber */, implicit-def dead early-clobber $x29, 12 /* clobber */, implicit-def dead early-clobber $x31
+  ; ZDINX-NEXT:   renamable $x10_x11 = PseudoRV32ZdinxLD $x2, 8 :: (load (s64) from %stack.0, align 4)
+  ; ZDINX-NEXT:   $x8 = frame-destroy LW $x2, 60 :: (load (s32) from %stack.1)
+  ; ZDINX-NEXT:   $x9 = frame-destroy LW $x2, 56 :: (load (s32) from %stack.2)
+  ; ZDINX-NEXT:   $x18 = frame-destroy LW $x2, 52 :: (load (s32) from %stack.3)
+  ; ZDINX-NEXT:   $x19 = frame-destroy LW $x2, 48 :: (load (s32) from %stack.4)
+  ; ZDINX-NEXT:   $x20 = frame-destroy LW $x2, 44 :: (load (s32) from %stack.5)
+  ; ZDINX-NEXT:   $x21 = frame-destroy LW $x2, 40 :: (load (s32) from %stack.6)
+  ; ZDINX-NEXT:   $x22 = frame-destroy LW $x2, 36 :: (load (s32) from %stack.7)
+  ; ZDINX-NEXT:   $x23 = frame-destroy LW $x2, 32 :: (load (s32) from %stack.8)
+  ; ZDINX-NEXT:   $x24 = frame-destroy LW $x2, 28 :: (load (s32) from %stack.9)
+  ; ZDINX-NEXT:   $x25 = frame-destroy LW $x2, 24 :: (load (s32) from %stack.10)
+  ; ZDINX-NEXT:   $x26 = frame-destroy LW $x2, 20 :: (load (s32) from %stack.11)
+  ; ZDINX-NEXT:   $x27 = frame-destroy LW $x2, 16 :: (load (s32) from %stack.12)
+  ; ZDINX-NEXT:   $x2 = frame-destroy ADDI $x2, 64
+  ; ZDINX-NEXT:   PseudoRET implicit $x10, implicit $x11
+  ;
+  ; ZDINX-ZILSD-LABEL: name: foo
+  ; ZDINX-ZILSD: bb.0 (%ir-block.0):
+  ; ZDINX-ZILSD-NEXT:   liveins: $x10, $x11, $x8, $x9, $x18, $x19, $x20, $x21, $x22, $x23, $x24, $x25, $x26, $x27
+  ; ZDINX-ZILSD-NEXT: {{  $}}
+  ; ZDINX-ZILSD-NEXT:   $x2 = frame-setup ADDI $x2, -64
+  ; ZDINX-ZILSD-NEXT:   frame-setup SW killed $x8, $x2, 60 :: (store (s32) into %stack.1)
+  ; ZDINX-ZILSD-NEXT:   frame-setup SW killed $x9, $x2, 56 :: (store (s32) into %stack.2)
+  ; ZDINX-ZILSD-NEXT:   frame-setup SW killed $x18, $x2, 52 :: (store (s32) into %stack.3)
+  ; ZDINX-ZILSD-NEXT:   frame-setup SW killed $x19, $x2, 48 :: (store (s32) into %stack.4)
+  ; ZDINX-ZILSD-NEXT:   frame-setup SW killed $x20, $x2, 44 :: (store (s32) into %stack.5)
+  ; ZDINX-ZILSD-NEXT:   frame-setup SW killed $x21, $x2, 40 :: (store (s32) into %stack.6)
+  ; ZDINX-ZILSD-NEXT:   frame-setup SW killed $x22, $x2, 36 :: (store (s32) into %stack.7)
+  ; ZDINX-ZILSD-NEXT:   frame-setup SW killed $x23, $x2, 32 :: (store (s32) into %stack.8)
+  ; ZDINX-ZILSD-NEXT:   frame-setup SW killed $x24, $x2, 28 :: (store (s32) into %stack.9)
+  ; ZDINX-ZILSD-NEXT:   frame-setup SW killed $x25, $x2, 24 :: (store (s32) into %stack.10)
+  ; ZDINX-ZILSD-NEXT:   frame-setup SW killed $x26, $x2, 20 :: (store (s32) into %stack.11)
+  ; ZDINX-ZILSD-NEXT:   frame-setup SW killed $x27, $x2, 16 :: (store (s32) into %stack.12)
+  ; ZDINX-ZILSD-NEXT:   renamable $x10_x11 = nofpexcept FADD_D_IN32X killed renamable $x10_x11, renamable $x10_x11, 7, implicit $frm
+  ; ZDINX-ZILSD-NEXT:   SD_RV32 killed renamable $x10_x11, $x2, 8 :: (store (s64) into %stack.0, align 4)
+  ; ZDINX-ZILSD-NEXT:   INLINEASM &"", 1 /* sideeffect attdialect */, 12 /* clobber */, implicit-def dead early-clobber $x6, 12 /* clobber */, implicit-def dead early-clobber $x7, 12 /* clobber */, implicit-def dead early-clobber $x8, 12 /* clobber */, implicit-def dead early-clobber $x9, 12 /* clobber */, implicit-def dead early-clobber $x10, 12 /* clobber */, implicit-def dead early-clobber $x11, 12 /* clobber */, implicit-def dead early-clobber $x12, 12 /* clobber */, implicit-def dead early-clobber $x13, 12 /* clobber */, implicit-def dead early-clobber $x14, 12 /* clobber */, implicit-def dead early-clobber $x15, 12 /* clobber */, implicit-def dead early-clobber $x16, 12 /* clobber */, implicit-def dead early-clobber $x17, 12 /* clobber */, implicit-def dead early-clobber $x18, 12 /* clobber */, implicit-def dead early-clobber $x19, 12 /* clobber */, implicit-def dead early-clobber $x20, 12 /* clobber */, implicit-def dead early-clobber $x21, 12 /* clobber */, implicit-def dead early-clobber $x22, 12 /* clobber */, implicit-def dead early-clobber $x23, 12 /* clobber */, implicit-def dead early-clobber $x24, 12 /* clobber */, implicit-def dead early-clobber $x25, 12 /* clobber */, implicit-def dead early-clobber $x26, 12 /* clobber */, implicit-def dead early-clobber $x27, 12 /* clobber */, implicit-def dead early-clobber $x28, 12 /* clobber */, implicit-def dead early-clobber $x29, 12 /* clobber */, implicit-def dead early-clobber $x31
+  ; ZDINX-ZILSD-NEXT:   renamable $x10_x11 = LD_RV32 $x2, 8 :: (load (s64) from %stack.0, align 4)
+  ; ZDINX-ZILSD-NEXT:   $x8 = frame-destroy LW $x2, 60 :: (load (s32) from %stack.1)
+  ; ZDINX-ZILSD-NEXT:   $x9 = frame-destroy LW $x2, 56 :: (load (s32) from %stack.2)
+  ; ZDINX-ZILSD-NEXT:   $x18 = frame-destroy LW $x2, 52 :: (load (s32) from %stack.3)
+  ; ZDINX-ZILSD-NEXT:   $x19 = frame-destroy LW $x2, 48 :: (load (s32) from %stack.4)
+  ; ZDINX-ZILSD-NEXT:   $x20 = frame-destroy LW $x2, 44 :: (load (s32) from %stack.5)
+  ; ZDINX-ZILSD-NEXT:   $x21 = frame-destroy LW $x2, 40 :: (load (s32) from %stack.6)
+  ; ZDINX-ZILSD-NEXT:   $x22 = frame-destroy LW $x2, 36 :: (load (s32) from %stack.7)
+  ; ZDINX-ZILSD-NEXT:   $x23 = frame-destroy LW $x2, 32 :: (load (s32) from %stack.8)
+  ; ZDINX-ZILSD-NEXT:   $x24 = frame-destroy LW $x2, 28 :: (load (s32) from %stack.9)
+  ; ZDINX-ZILSD-NEXT:   $x25 = frame-destroy LW $x2, 24 :: (load (s32) from %stack.10)
+  ; ZDINX-ZILSD-NEXT:   $x26 = frame-destroy LW $x2, 20 :: (load (s32) from %stack.11)
+  ; ZDINX-ZILSD-NEXT:   $x27 = frame-destroy LW $x2, 16 :: (load (s32) from %stack.12)
+  ; ZDINX-ZILSD-NEXT:   $x2 = frame-destroy ADDI $x2, 64
+  ; ZDINX-ZILSD-NEXT:   PseudoRET implicit $x10, implicit $x11
   %a = fadd double %x, %x
   call void asm sideeffect "", "~{x6},~{x7},~{x8},~{x9},~{x10},~{x11},~{x12},~{x13},~{x14},~{x15},~{x16},~{x17},~{x18},~{x19},~{x20},~{x21},~{x22},~{x23},~{x24},~{x25},~{x26},~{x27},~{x28},~{x29},~{xr0},~{x31}"()
   ret double %a

``````````

</details>


https://github.com/llvm/llvm-project/pull/153595


More information about the llvm-commits mailing list