[llvm] [RISCV][GISel] Use the correct calling convention during call lowering (PR #142148)

Matt Arsenault via llvm-commits llvm-commits at lists.llvm.org
Fri May 30 08:10:26 PDT 2025


https://github.com/arsenm updated https://github.com/llvm/llvm-project/pull/142148

>From bc504b01c02393fa81791a457545aa25a15b5aa2 Mon Sep 17 00:00:00 2001
From: Florian Drescher <florian.drescher at tum.de>
Date: Fri, 30 May 2025 15:30:36 +0200
Subject: [PATCH 1/2] [RISCV][GISel] Use the correct calling convention during
 call lowering

Correctly use the calling convention of the callee during call lowering (not the calling convention of the caller)
---
 .../Target/RISCV/GISel/RISCVCallLowering.cpp  |   2 +-
 llvm/test/CodeGen/RISCV/GlobalISel/calls.ll   | 113 ++++++++++++
 llvm/test/CodeGen/RISCV/calls.ll              | 162 ++++++++++++++++++
 3 files changed, 276 insertions(+), 1 deletion(-)
 create mode 100644 llvm/test/CodeGen/RISCV/GlobalISel/calls.ll

diff --git a/llvm/lib/Target/RISCV/GISel/RISCVCallLowering.cpp b/llvm/lib/Target/RISCV/GISel/RISCVCallLowering.cpp
index 67560072d311d..d566fa637c9f6 100644
--- a/llvm/lib/Target/RISCV/GISel/RISCVCallLowering.cpp
+++ b/llvm/lib/Target/RISCV/GISel/RISCVCallLowering.cpp
@@ -588,7 +588,7 @@ bool RISCVCallLowering::lowerCall(MachineIRBuilder &MIRBuilder,
   MachineFunction &MF = MIRBuilder.getMF();
   const DataLayout &DL = MF.getDataLayout();
   const Function &F = MF.getFunction();
-  CallingConv::ID CC = F.getCallingConv();
+  CallingConv::ID CC = Info.CallConv;
 
   const RISCVSubtarget &Subtarget =
       MIRBuilder.getMF().getSubtarget<RISCVSubtarget>();
diff --git a/llvm/test/CodeGen/RISCV/GlobalISel/calls.ll b/llvm/test/CodeGen/RISCV/GlobalISel/calls.ll
new file mode 100644
index 0000000000000..d4cc40411470b
--- /dev/null
+++ b/llvm/test/CodeGen/RISCV/GlobalISel/calls.ll
@@ -0,0 +1,113 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mtriple=riscv32 -verify-machineinstrs -global-isel < %s \
+; RUN:   | FileCheck -check-prefixes=CHECK,RV32I %s
+; RUN: llc -mtriple=riscv64 -verify-machineinstrs -global-isel < %s \
+; RUN:   | FileCheck -check-prefix=RV64I %s
+
+declare i32 @external_many_args(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) nounwind
+
+define i32 @test_call_external_many_args(i32 %a) nounwind {
+; CHECK-LABEL: test_call_external_many_args:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    addi sp, sp, -16
+; CHECK-NEXT:    sw ra, 12(sp) # 4-byte Folded Spill
+; CHECK-NEXT:    sw s0, 8(sp) # 4-byte Folded Spill
+; CHECK-NEXT:    mv s0, a0
+; CHECK-NEXT:    sw a0, 0(sp)
+; CHECK-NEXT:    sw a0, 4(sp)
+; CHECK-NEXT:    mv a1, a0
+; CHECK-NEXT:    mv a2, a0
+; CHECK-NEXT:    mv a3, a0
+; CHECK-NEXT:    mv a4, a0
+; CHECK-NEXT:    mv a5, a0
+; CHECK-NEXT:    mv a6, a0
+; CHECK-NEXT:    mv a7, a0
+; CHECK-NEXT:    call external_many_args
+; CHECK-NEXT:    mv a0, s0
+; CHECK-NEXT:    lw ra, 12(sp) # 4-byte Folded Reload
+; CHECK-NEXT:    lw s0, 8(sp) # 4-byte Folded Reload
+; CHECK-NEXT:    addi sp, sp, 16
+; CHECK-NEXT:    ret
+;
+; RV64I-LABEL: test_call_external_many_args:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    addi sp, sp, -32
+; RV64I-NEXT:    sd ra, 24(sp) # 8-byte Folded Spill
+; RV64I-NEXT:    sd s0, 16(sp) # 8-byte Folded Spill
+; RV64I-NEXT:    mv s0, a0
+; RV64I-NEXT:    sd a0, 0(sp)
+; RV64I-NEXT:    sd a0, 8(sp)
+; RV64I-NEXT:    mv a1, a0
+; RV64I-NEXT:    mv a2, a0
+; RV64I-NEXT:    mv a3, a0
+; RV64I-NEXT:    mv a4, a0
+; RV64I-NEXT:    mv a5, a0
+; RV64I-NEXT:    mv a6, a0
+; RV64I-NEXT:    mv a7, a0
+; RV64I-NEXT:    call external_many_args
+; RV64I-NEXT:    mv a0, s0
+; RV64I-NEXT:    ld ra, 24(sp) # 8-byte Folded Reload
+; RV64I-NEXT:    ld s0, 16(sp) # 8-byte Folded Reload
+; RV64I-NEXT:    addi sp, sp, 32
+; RV64I-NEXT:    ret
+  %1 = call i32 @external_many_args(i32 %a, i32 %a, i32 %a, i32 %a, i32 %a,
+                                    i32 %a, i32 %a, i32 %a, i32 %a, i32 %a)
+  ret i32 %a
+}
+
+define fastcc void @fastcc_call_nonfastcc(){
+; CHECK-LABEL: fastcc_call_nonfastcc:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    addi sp, sp, -16
+; CHECK-NEXT:    .cfi_def_cfa_offset 16
+; CHECK-NEXT:    sw ra, 12(sp) # 4-byte Folded Spill
+; CHECK-NEXT:    .cfi_offset ra, -4
+; CHECK-NEXT:    li t0, 9
+; CHECK-NEXT:    li t1, 10
+; CHECK-NEXT:    li a0, 1
+; CHECK-NEXT:    li a1, 2
+; CHECK-NEXT:    li a2, 3
+; CHECK-NEXT:    li a3, 4
+; CHECK-NEXT:    li a4, 5
+; CHECK-NEXT:    li a5, 6
+; CHECK-NEXT:    li a6, 7
+; CHECK-NEXT:    li a7, 8
+; CHECK-NEXT:    sw t0, 0(sp)
+; CHECK-NEXT:    sw t1, 4(sp)
+; CHECK-NEXT:    call external_many_args
+; CHECK-NEXT:    lw ra, 12(sp) # 4-byte Folded Reload
+; CHECK-NEXT:    .cfi_restore ra
+; CHECK-NEXT:    addi sp, sp, 16
+; CHECK-NEXT:    .cfi_def_cfa_offset 0
+; CHECK-NEXT:    ret
+;
+; RV64I-LABEL: fastcc_call_nonfastcc:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    addi sp, sp, -32
+; RV64I-NEXT:    .cfi_def_cfa_offset 32
+; RV64I-NEXT:    sd ra, 24(sp) # 8-byte Folded Spill
+; RV64I-NEXT:    .cfi_offset ra, -8
+; RV64I-NEXT:    li t0, 9
+; RV64I-NEXT:    li t1, 10
+; RV64I-NEXT:    li a0, 1
+; RV64I-NEXT:    li a1, 2
+; RV64I-NEXT:    li a2, 3
+; RV64I-NEXT:    li a3, 4
+; RV64I-NEXT:    li a4, 5
+; RV64I-NEXT:    li a5, 6
+; RV64I-NEXT:    li a6, 7
+; RV64I-NEXT:    li a7, 8
+; RV64I-NEXT:    sd t0, 0(sp)
+; RV64I-NEXT:    sd t1, 8(sp)
+; RV64I-NEXT:    call external_many_args
+; RV64I-NEXT:    ld ra, 24(sp) # 8-byte Folded Reload
+; RV64I-NEXT:    .cfi_restore ra
+; RV64I-NEXT:    addi sp, sp, 32
+; RV64I-NEXT:    .cfi_def_cfa_offset 0
+; RV64I-NEXT:    ret
+  call void @external_many_args(i32 1, i32 2,i32 3,i32 4,i32 5,i32 6,i32 7,i32 8,i32 9,i32 10)
+  ret void
+}
+
+;; NOTE: These prefixes are unused and the list is autogenerated. Do not add tests below this line:
+; RV32I: {{.*}}
diff --git a/llvm/test/CodeGen/RISCV/calls.ll b/llvm/test/CodeGen/RISCV/calls.ll
index cf0e625f3c6c7..f30c453d7f6bc 100644
--- a/llvm/test/CodeGen/RISCV/calls.ll
+++ b/llvm/test/CodeGen/RISCV/calls.ll
@@ -865,6 +865,168 @@ define i32 @test_call_defined_many_args(i32 %a) nounwind {
                                    i32 %a, i32 %a, i32 %a, i32 %a, i32 %a)
   ret i32 %1
 }
+
+define fastcc void @fastcc_call_nonfastcc(){
+; CHECK-LABEL: fastcc_call_nonfastcc:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    addi sp, sp, -16
+; CHECK-NEXT:    .cfi_def_cfa_offset 16
+; CHECK-NEXT:    sw ra, 12(sp) # 4-byte Folded Spill
+; CHECK-NEXT:    .cfi_offset ra, -4
+; CHECK-NEXT:    li t0, 10
+; CHECK-NEXT:    li t1, 9
+; CHECK-NEXT:    li a0, 1
+; CHECK-NEXT:    li a1, 2
+; CHECK-NEXT:    li a2, 3
+; CHECK-NEXT:    li a3, 4
+; CHECK-NEXT:    li a4, 5
+; CHECK-NEXT:    li a5, 6
+; CHECK-NEXT:    li a6, 7
+; CHECK-NEXT:    li a7, 8
+; CHECK-NEXT:    sw t1, 0(sp)
+; CHECK-NEXT:    sw t0, 4(sp)
+; CHECK-NEXT:    call external_many_args
+; CHECK-NEXT:    lw ra, 12(sp) # 4-byte Folded Reload
+; CHECK-NEXT:    .cfi_restore ra
+; CHECK-NEXT:    addi sp, sp, 16
+; CHECK-NEXT:    .cfi_def_cfa_offset 0
+; CHECK-NEXT:    ret
+;
+; RV64I-LABEL: fastcc_call_nonfastcc:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    addi sp, sp, -32
+; RV64I-NEXT:    .cfi_def_cfa_offset 32
+; RV64I-NEXT:    sd ra, 24(sp) # 8-byte Folded Spill
+; RV64I-NEXT:    .cfi_offset ra, -8
+; RV64I-NEXT:    li t0, 10
+; RV64I-NEXT:    li t1, 9
+; RV64I-NEXT:    li a0, 1
+; RV64I-NEXT:    li a1, 2
+; RV64I-NEXT:    li a2, 3
+; RV64I-NEXT:    li a3, 4
+; RV64I-NEXT:    li a4, 5
+; RV64I-NEXT:    li a5, 6
+; RV64I-NEXT:    li a6, 7
+; RV64I-NEXT:    li a7, 8
+; RV64I-NEXT:    sd t1, 0(sp)
+; RV64I-NEXT:    sd t0, 8(sp)
+; RV64I-NEXT:    call external_many_args
+; RV64I-NEXT:    ld ra, 24(sp) # 8-byte Folded Reload
+; RV64I-NEXT:    .cfi_restore ra
+; RV64I-NEXT:    addi sp, sp, 32
+; RV64I-NEXT:    .cfi_def_cfa_offset 0
+; RV64I-NEXT:    ret
+;
+; RV64I-SMALL-LABEL: fastcc_call_nonfastcc:
+; RV64I-SMALL:       # %bb.0:
+; RV64I-SMALL-NEXT:    addi sp, sp, -32
+; RV64I-SMALL-NEXT:    .cfi_def_cfa_offset 32
+; RV64I-SMALL-NEXT:    sd ra, 24(sp) # 8-byte Folded Spill
+; RV64I-SMALL-NEXT:    .cfi_offset ra, -8
+; RV64I-SMALL-NEXT:    li t0, 10
+; RV64I-SMALL-NEXT:    li t1, 9
+; RV64I-SMALL-NEXT:    li a0, 1
+; RV64I-SMALL-NEXT:    li a1, 2
+; RV64I-SMALL-NEXT:    li a2, 3
+; RV64I-SMALL-NEXT:    li a3, 4
+; RV64I-SMALL-NEXT:    li a4, 5
+; RV64I-SMALL-NEXT:    li a5, 6
+; RV64I-SMALL-NEXT:    li a6, 7
+; RV64I-SMALL-NEXT:    li a7, 8
+; RV64I-SMALL-NEXT:    sd t1, 0(sp)
+; RV64I-SMALL-NEXT:    sd t0, 8(sp)
+; RV64I-SMALL-NEXT:    call external_many_args
+; RV64I-SMALL-NEXT:    ld ra, 24(sp) # 8-byte Folded Reload
+; RV64I-SMALL-NEXT:    .cfi_restore ra
+; RV64I-SMALL-NEXT:    addi sp, sp, 32
+; RV64I-SMALL-NEXT:    .cfi_def_cfa_offset 0
+; RV64I-SMALL-NEXT:    ret
+;
+; RV64I-MEDIUM-LABEL: fastcc_call_nonfastcc:
+; RV64I-MEDIUM:       # %bb.0:
+; RV64I-MEDIUM-NEXT:    addi sp, sp, -32
+; RV64I-MEDIUM-NEXT:    .cfi_def_cfa_offset 32
+; RV64I-MEDIUM-NEXT:    sd ra, 24(sp) # 8-byte Folded Spill
+; RV64I-MEDIUM-NEXT:    .cfi_offset ra, -8
+; RV64I-MEDIUM-NEXT:    li t0, 10
+; RV64I-MEDIUM-NEXT:    li t1, 9
+; RV64I-MEDIUM-NEXT:    li a0, 1
+; RV64I-MEDIUM-NEXT:    li a1, 2
+; RV64I-MEDIUM-NEXT:    li a2, 3
+; RV64I-MEDIUM-NEXT:    li a3, 4
+; RV64I-MEDIUM-NEXT:    li a4, 5
+; RV64I-MEDIUM-NEXT:    li a5, 6
+; RV64I-MEDIUM-NEXT:    li a6, 7
+; RV64I-MEDIUM-NEXT:    li a7, 8
+; RV64I-MEDIUM-NEXT:    sd t1, 0(sp)
+; RV64I-MEDIUM-NEXT:    sd t0, 8(sp)
+; RV64I-MEDIUM-NEXT:    call external_many_args
+; RV64I-MEDIUM-NEXT:    ld ra, 24(sp) # 8-byte Folded Reload
+; RV64I-MEDIUM-NEXT:    .cfi_restore ra
+; RV64I-MEDIUM-NEXT:    addi sp, sp, 32
+; RV64I-MEDIUM-NEXT:    .cfi_def_cfa_offset 0
+; RV64I-MEDIUM-NEXT:    ret
+;
+; RV64I-LARGE-LABEL: fastcc_call_nonfastcc:
+; RV64I-LARGE:       # %bb.0:
+; RV64I-LARGE-NEXT:    addi sp, sp, -32
+; RV64I-LARGE-NEXT:    .cfi_def_cfa_offset 32
+; RV64I-LARGE-NEXT:    sd ra, 24(sp) # 8-byte Folded Spill
+; RV64I-LARGE-NEXT:    .cfi_offset ra, -8
+; RV64I-LARGE-NEXT:    li t0, 10
+; RV64I-LARGE-NEXT:    li t1, 9
+; RV64I-LARGE-NEXT:  .Lpcrel_hi6:
+; RV64I-LARGE-NEXT:    auipc a5, %pcrel_hi(.LCPI11_0)
+; RV64I-LARGE-NEXT:    li a0, 1
+; RV64I-LARGE-NEXT:    li a1, 2
+; RV64I-LARGE-NEXT:    li a2, 3
+; RV64I-LARGE-NEXT:    li a3, 4
+; RV64I-LARGE-NEXT:    li a4, 5
+; RV64I-LARGE-NEXT:    ld t2, %pcrel_lo(.Lpcrel_hi6)(a5)
+; RV64I-LARGE-NEXT:    li a5, 6
+; RV64I-LARGE-NEXT:    li a6, 7
+; RV64I-LARGE-NEXT:    li a7, 8
+; RV64I-LARGE-NEXT:    sd t1, 0(sp)
+; RV64I-LARGE-NEXT:    sd t0, 8(sp)
+; RV64I-LARGE-NEXT:    jalr t2
+; RV64I-LARGE-NEXT:    ld ra, 24(sp) # 8-byte Folded Reload
+; RV64I-LARGE-NEXT:    .cfi_restore ra
+; RV64I-LARGE-NEXT:    addi sp, sp, 32
+; RV64I-LARGE-NEXT:    .cfi_def_cfa_offset 0
+; RV64I-LARGE-NEXT:    ret
+;
+; RV64I-LARGE-ZICFILP-LABEL: fastcc_call_nonfastcc:
+; RV64I-LARGE-ZICFILP:       # %bb.0:
+; RV64I-LARGE-ZICFILP-NEXT:    lpad 0
+; RV64I-LARGE-ZICFILP-NEXT:    addi sp, sp, -32
+; RV64I-LARGE-ZICFILP-NEXT:    .cfi_def_cfa_offset 32
+; RV64I-LARGE-ZICFILP-NEXT:    sd ra, 24(sp) # 8-byte Folded Spill
+; RV64I-LARGE-ZICFILP-NEXT:    .cfi_offset ra, -8
+; RV64I-LARGE-ZICFILP-NEXT:    li t0, 10
+; RV64I-LARGE-ZICFILP-NEXT:    li t1, 9
+; RV64I-LARGE-ZICFILP-NEXT:  .Lpcrel_hi6:
+; RV64I-LARGE-ZICFILP-NEXT:    auipc a5, %pcrel_hi(.LCPI11_0)
+; RV64I-LARGE-ZICFILP-NEXT:    li a0, 1
+; RV64I-LARGE-ZICFILP-NEXT:    li a1, 2
+; RV64I-LARGE-ZICFILP-NEXT:    li a2, 3
+; RV64I-LARGE-ZICFILP-NEXT:    li a3, 4
+; RV64I-LARGE-ZICFILP-NEXT:    li a4, 5
+; RV64I-LARGE-ZICFILP-NEXT:    ld t2, %pcrel_lo(.Lpcrel_hi6)(a5)
+; RV64I-LARGE-ZICFILP-NEXT:    li a5, 6
+; RV64I-LARGE-ZICFILP-NEXT:    li a6, 7
+; RV64I-LARGE-ZICFILP-NEXT:    li a7, 8
+; RV64I-LARGE-ZICFILP-NEXT:    sd t1, 0(sp)
+; RV64I-LARGE-ZICFILP-NEXT:    sd t0, 8(sp)
+; RV64I-LARGE-ZICFILP-NEXT:    jalr t2
+; RV64I-LARGE-ZICFILP-NEXT:    ld ra, 24(sp) # 8-byte Folded Reload
+; RV64I-LARGE-ZICFILP-NEXT:    .cfi_restore ra
+; RV64I-LARGE-ZICFILP-NEXT:    addi sp, sp, 32
+; RV64I-LARGE-ZICFILP-NEXT:    .cfi_def_cfa_offset 0
+; RV64I-LARGE-ZICFILP-NEXT:    ret
+  call void @external_many_args(i32 1, i32 2,i32 3,i32 4,i32 5,i32 6,i32 7,i32 8,i32 9,i32 10)
+  ret void
+}
+
 ;; NOTE: These prefixes are unused and the list is autogenerated. Do not add tests below this line:
 ; RV32I: {{.*}}
 ; RV32I-PIC: {{.*}}

>From 1377e676138ffc44680b24ebd335ccfa9bfced7a Mon Sep 17 00:00:00 2001
From: Matt Arsenault <arsenm2 at gmail.com>
Date: Fri, 30 May 2025 17:10:18 +0200
Subject: [PATCH 2/2] Update llvm/test/CodeGen/RISCV/GlobalISel/calls.ll

---
 llvm/test/CodeGen/RISCV/GlobalISel/calls.ll | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/llvm/test/CodeGen/RISCV/GlobalISel/calls.ll b/llvm/test/CodeGen/RISCV/GlobalISel/calls.ll
index d4cc40411470b..2a655bfb00693 100644
--- a/llvm/test/CodeGen/RISCV/GlobalISel/calls.ll
+++ b/llvm/test/CodeGen/RISCV/GlobalISel/calls.ll
@@ -1,8 +1,6 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
-; RUN: llc -mtriple=riscv32 -verify-machineinstrs -global-isel < %s \
-; RUN:   | FileCheck -check-prefixes=CHECK,RV32I %s
-; RUN: llc -mtriple=riscv64 -verify-machineinstrs -global-isel < %s \
-; RUN:   | FileCheck -check-prefix=RV64I %s
+; RUN: llc -global-isel -mtriple=riscv32 < %s | FileCheck -check-prefixes=CHECK,RV32I %s
+; RUN: llc -global-isel -mtriple=riscv64 < %s | FileCheck -check-prefix=RV64I %s
 
 declare i32 @external_many_args(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32) nounwind
 



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