[llvm] [RISCV][CFI] Emit cfi_offset for every callee-saved vector registers (PR #100455)
via llvm-commits
llvm-commits at lists.llvm.org
Wed Jul 24 12:50:29 PDT 2024
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-backend-risc-v
Author: Brandon Wu (4vtomat)
<details>
<summary>Changes</summary>
The grouped vector register is modeled as a single register, e.g. V2M2,
which is actually V2 and V3. We need to decompose the grouped vector
register(if any) to individual vector register when emitting CFIs in
prologue.
Fixed https://github.com/llvm/llvm-project/issues/94500
---
Full diff: https://github.com/llvm/llvm-project/pull/100455.diff
2 Files Affected:
- (modified) llvm/lib/Target/RISCV/RISCVFrameLowering.cpp (+38-6)
- (modified) llvm/test/CodeGen/RISCV/rvv-cfi-info.ll (+12-4)
``````````diff
diff --git a/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp b/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp
index e676c2f94583d..23acea987d2c7 100644
--- a/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp
@@ -53,6 +53,35 @@ static const std::pair<MCPhysReg, int8_t> FixedCSRFIMap[] = {
{/*s9*/ RISCV::X25, -11}, {/*s10*/ RISCV::X26, -12},
{/*s11*/ RISCV::X27, -13}};
+// This function returns {Base VReg, corresponding LMUL} of callee-saved VReg.
+// For example:
+// V2M2 -> {RISCV::V2, 2}
+// V8 -> {RISCV::V8, 1}
+static std::pair<MCPhysReg, int8_t> getCSBaseVRegLMULPair(MCPhysReg VR) {
+ assert(((VR >= RISCV::V1 && VR <= RISCV::V7) ||
+ (VR >= RISCV::V24 && VR <= RISCV::V31) ||
+ (VR >= RISCV::V2M2 && VR <= RISCV::V6M2) ||
+ (VR >= RISCV::V24M2 && VR <= RISCV::V30M2)) &&
+ "Invalid VR");
+
+ static constexpr std::pair<MCPhysReg, int8_t> VRegLMULLUT[] = {
+ {/*V2M2*/ RISCV::V2, 2}, {/*V4M2*/ RISCV::V4, 2},
+ {/*V4M4*/ RISCV::V4, 4}, {/*V6M2*/ RISCV::V6, 2},
+ {/*V24M2*/ RISCV::V24, 2}, {/*V24M4*/ RISCV::V24, 4},
+ {/*V24M8*/ RISCV::V24, 8}, {/*V26M2*/ RISCV::V26, 2},
+ {/*V28M2*/ RISCV::V28, 2}, {/*V28M4*/ RISCV::V28, 4},
+ {/*V30M2*/ RISCV::V30, 2}};
+
+ if ((VR >= RISCV::V1 && VR <= RISCV::V7) ||
+ (VR >= RISCV::V24 && VR <= RISCV::V31))
+ return std::make_pair(VR, 1);
+
+ if (VR >= RISCV::V2M2 && VR <= RISCV::V6M2)
+ return VRegLMULLUT[VR - RISCV::V2M2];
+
+ return VRegLMULLUT[VR - RISCV::V24M2 + 4];
+}
+
// For now we use x3, a.k.a gp, as pointer to shadow call stack.
// User should not use x3 in their asm.
static void emitSCSPrologue(MachineFunction &MF, MachineBasicBlock &MBB,
@@ -1554,12 +1583,15 @@ void RISCVFrameLowering::emitCalleeSavedRVVPrologCFI(
// Insert the spill to the stack frame.
int FI = CS.getFrameIdx();
if (FI >= 0 && MFI.getStackID(FI) == TargetStackID::ScalableVector) {
- unsigned CFIIndex = MF->addFrameInst(
- createDefCFAOffset(*STI.getRegisterInfo(), CS.getReg(), -FixedSize,
- MFI.getObjectOffset(FI) / 8));
- BuildMI(MBB, MI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
- .addCFIIndex(CFIIndex)
- .setMIFlag(MachineInstr::FrameSetup);
+ auto VRegLMULPair = getCSBaseVRegLMULPair(CS.getReg());
+ for (int i = 0; i < VRegLMULPair.second; ++i) {
+ unsigned CFIIndex = MF->addFrameInst(
+ createDefCFAOffset(*STI.getRegisterInfo(), VRegLMULPair.first + i,
+ -FixedSize, MFI.getObjectOffset(FI) / 8 + i));
+ BuildMI(MBB, MI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
+ .addCFIIndex(CFIIndex)
+ .setMIFlag(MachineInstr::FrameSetup);
+ }
}
}
}
diff --git a/llvm/test/CodeGen/RISCV/rvv-cfi-info.ll b/llvm/test/CodeGen/RISCV/rvv-cfi-info.ll
index c99388cbdaf44..93fe66695b70e 100644
--- a/llvm/test/CodeGen/RISCV/rvv-cfi-info.ll
+++ b/llvm/test/CodeGen/RISCV/rvv-cfi-info.ll
@@ -27,8 +27,12 @@ define riscv_vector_cc <vscale x 1 x i32> @test_vector_callee_cfi(<vscale x 1 x
; OMIT-FP-NEXT: addi a0, sp, 16
; OMIT-FP-NEXT: vs4r.v v4, (a0) # Unknown-size Folded Spill
; OMIT-FP-NEXT: .cfi_escape 0x10, 0x61, 0x08, 0x11, 0x7e, 0x92, 0xa2, 0x38, 0x00, 0x1e, 0x22 # $v1 @ cfa - 2 * vlenb
-; OMIT-FP-NEXT: .cfi_escape 0x10, 0x62, 0x08, 0x11, 0x7c, 0x92, 0xa2, 0x38, 0x00, 0x1e, 0x22 # $v2m2 @ cfa - 4 * vlenb
-; OMIT-FP-NEXT: .cfi_escape 0x10, 0x64, 0x08, 0x11, 0x78, 0x92, 0xa2, 0x38, 0x00, 0x1e, 0x22 # $v4m4 @ cfa - 8 * vlenb
+; OMIT-FP-NEXT: .cfi_escape 0x10, 0x62, 0x08, 0x11, 0x7c, 0x92, 0xa2, 0x38, 0x00, 0x1e, 0x22 # $v2 @ cfa - 4 * vlenb
+; OMIT-FP-NEXT: .cfi_escape 0x10, 0x63, 0x08, 0x11, 0x7d, 0x92, 0xa2, 0x38, 0x00, 0x1e, 0x22 # $v3 @ cfa - 3 * vlenb
+; OMIT-FP-NEXT: .cfi_escape 0x10, 0x64, 0x08, 0x11, 0x78, 0x92, 0xa2, 0x38, 0x00, 0x1e, 0x22 # $v4 @ cfa - 8 * vlenb
+; OMIT-FP-NEXT: .cfi_escape 0x10, 0x65, 0x08, 0x11, 0x79, 0x92, 0xa2, 0x38, 0x00, 0x1e, 0x22 # $v5 @ cfa - 7 * vlenb
+; OMIT-FP-NEXT: .cfi_escape 0x10, 0x66, 0x08, 0x11, 0x7a, 0x92, 0xa2, 0x38, 0x00, 0x1e, 0x22 # $v6 @ cfa - 6 * vlenb
+; OMIT-FP-NEXT: .cfi_escape 0x10, 0x67, 0x08, 0x11, 0x7b, 0x92, 0xa2, 0x38, 0x00, 0x1e, 0x22 # $v7 @ cfa - 5 * vlenb
; OMIT-FP-NEXT: #APP
; OMIT-FP-NEXT: #NO_APP
; OMIT-FP-NEXT: csrr a0, vlenb
@@ -79,8 +83,12 @@ define riscv_vector_cc <vscale x 1 x i32> @test_vector_callee_cfi(<vscale x 1 x
; NO-OMIT-FP-NEXT: addi a0, a0, -32
; NO-OMIT-FP-NEXT: vs4r.v v4, (a0) # Unknown-size Folded Spill
; NO-OMIT-FP-NEXT: .cfi_escape 0x10, 0x61, 0x0b, 0x11, 0x60, 0x22, 0x11, 0x7e, 0x92, 0xa2, 0x38, 0x00, 0x1e, 0x22 # $v1 @ cfa - 32 - 2 * vlenb
-; NO-OMIT-FP-NEXT: .cfi_escape 0x10, 0x62, 0x0b, 0x11, 0x60, 0x22, 0x11, 0x7c, 0x92, 0xa2, 0x38, 0x00, 0x1e, 0x22 # $v2m2 @ cfa - 32 - 4 * vlenb
-; NO-OMIT-FP-NEXT: .cfi_escape 0x10, 0x64, 0x0b, 0x11, 0x60, 0x22, 0x11, 0x78, 0x92, 0xa2, 0x38, 0x00, 0x1e, 0x22 # $v4m4 @ cfa - 32 - 8 * vlenb
+; NO-OMIT-FP-NEXT: .cfi_escape 0x10, 0x62, 0x0b, 0x11, 0x60, 0x22, 0x11, 0x7c, 0x92, 0xa2, 0x38, 0x00, 0x1e, 0x22 # $v2 @ cfa - 32 - 4 * vlenb
+; NO-OMIT-FP-NEXT: .cfi_escape 0x10, 0x63, 0x0b, 0x11, 0x60, 0x22, 0x11, 0x7d, 0x92, 0xa2, 0x38, 0x00, 0x1e, 0x22 # $v3 @ cfa - 32 - 3 * vlenb
+; NO-OMIT-FP-NEXT: .cfi_escape 0x10, 0x64, 0x0b, 0x11, 0x60, 0x22, 0x11, 0x78, 0x92, 0xa2, 0x38, 0x00, 0x1e, 0x22 # $v4 @ cfa - 32 - 8 * vlenb
+; NO-OMIT-FP-NEXT: .cfi_escape 0x10, 0x65, 0x0b, 0x11, 0x60, 0x22, 0x11, 0x79, 0x92, 0xa2, 0x38, 0x00, 0x1e, 0x22 # $v5 @ cfa - 32 - 7 * vlenb
+; NO-OMIT-FP-NEXT: .cfi_escape 0x10, 0x66, 0x0b, 0x11, 0x60, 0x22, 0x11, 0x7a, 0x92, 0xa2, 0x38, 0x00, 0x1e, 0x22 # $v6 @ cfa - 32 - 6 * vlenb
+; NO-OMIT-FP-NEXT: .cfi_escape 0x10, 0x67, 0x0b, 0x11, 0x60, 0x22, 0x11, 0x7b, 0x92, 0xa2, 0x38, 0x00, 0x1e, 0x22 # $v7 @ cfa - 32 - 5 * vlenb
; NO-OMIT-FP-NEXT: #APP
; NO-OMIT-FP-NEXT: #NO_APP
; NO-OMIT-FP-NEXT: csrr a0, vlenb
``````````
</details>
https://github.com/llvm/llvm-project/pull/100455
More information about the llvm-commits
mailing list