[llvm] 4eb4f89 - [RISCV] Use sign extend for i32 arguments and returns in makeLibCall on RV64.

[Craig Topper via llvm-commits]

Author: Craig Topper
Date: 2021-01-25T09:33:48-08:00
New Revision: 4eb4f8963f1e4998748bca66a512c3298f6d2289

URL: https://github.com/llvm/llvm-project/commit/4eb4f8963f1e4998748bca66a512c3298f6d2289
DIFF: https://github.com/llvm/llvm-project/commit/4eb4f8963f1e4998748bca66a512c3298f6d2289.diff

LOG: [RISCV] Use sign extend for i32 arguments and returns in makeLibCall on RV64.

As far as I know 32 bits arguments and returns on RV64 are always
sign extended to i64. So I think we should be taking this into
account around libcalls.

Reviewed By: luismarques

Differential Revision: https://reviews.llvm.org/D95285

Added: 
    

Modified: 
    llvm/lib/Target/RISCV/RISCVISelLowering.cpp
    llvm/lib/Target/RISCV/RISCVISelLowering.h
    llvm/test/CodeGen/RISCV/rv64i-single-softfloat.ll

Removed: 
    


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diff  --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
index 0f9da5600a34..54208fc187c9 100644
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -4250,6 +4250,13 @@ bool RISCVTargetLowering::shouldExtendTypeInLibCall(EVT Type) const {
   return true;
 }
 
+bool RISCVTargetLowering::shouldSignExtendTypeInLibCall(EVT Type, bool IsSigned) const {
+  if (Subtarget.is64Bit() && Type == MVT::i32)
+    return true;
+
+  return IsSigned;
+}
+
 bool RISCVTargetLowering::decomposeMulByConstant(LLVMContext &Context, EVT VT,
                                                  SDValue C) const {
   // Check integral scalar types.

diff  --git a/llvm/lib/Target/RISCV/RISCVISelLowering.h b/llvm/lib/Target/RISCV/RISCVISelLowering.h
index 3b7134341c8b..da16c6970d33 100644
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.h
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.h
@@ -217,6 +217,7 @@ class RISCVTargetLowering : public TargetLowering {
   getExceptionSelectorRegister(const Constant *PersonalityFn) const override;
 
   bool shouldExtendTypeInLibCall(EVT Type) const override;
+  bool shouldSignExtendTypeInLibCall(EVT Type, bool IsSigned) const override;
 
   /// Returns the register with the specified architectural or ABI name. This
   /// method is necessary to lower the llvm.read_register.* and

diff  --git a/llvm/test/CodeGen/RISCV/rv64i-single-softfloat.ll b/llvm/test/CodeGen/RISCV/rv64i-single-softfloat.ll
index 0b450c127077..31897d02e4c5 100644
--- a/llvm/test/CodeGen/RISCV/rv64i-single-softfloat.ll
+++ b/llvm/test/CodeGen/RISCV/rv64i-single-softfloat.ll
@@ -80,7 +80,6 @@ define i32 @flt_s(float %a, float %b) nounwind {
 ; RV64I-NEXT:    addi sp, sp, -16
 ; RV64I-NEXT:    sd ra, 8(sp) # 8-byte Folded Spill
 ; RV64I-NEXT:    call __ltsf2 at plt
-; RV64I-NEXT:    sext.w a0, a0
 ; RV64I-NEXT:    slti a0, a0, 0
 ; RV64I-NEXT:    ld ra, 8(sp) # 8-byte Folded Reload
 ; RV64I-NEXT:    addi sp, sp, 16
@@ -96,7 +95,6 @@ define i32 @fle_s(float %a, float %b) nounwind {
 ; RV64I-NEXT:    addi sp, sp, -16
 ; RV64I-NEXT:    sd ra, 8(sp) # 8-byte Folded Spill
 ; RV64I-NEXT:    call __lesf2 at plt
-; RV64I-NEXT:    sext.w a0, a0
 ; RV64I-NEXT:    slti a0, a0, 1
 ; RV64I-NEXT:    ld ra, 8(sp) # 8-byte Folded Reload
 ; RV64I-NEXT:    addi sp, sp, 16
@@ -112,7 +110,6 @@ define i32 @fcmp_ogt(float %a, float %b) nounwind {
 ; RV64I-NEXT:    addi sp, sp, -16
 ; RV64I-NEXT:    sd ra, 8(sp) # 8-byte Folded Spill
 ; RV64I-NEXT:    call __gtsf2 at plt
-; RV64I-NEXT:    sext.w a0, a0
 ; RV64I-NEXT:    sgtz a0, a0
 ; RV64I-NEXT:    ld ra, 8(sp) # 8-byte Folded Reload
 ; RV64I-NEXT:    addi sp, sp, 16
@@ -128,7 +125,6 @@ define i32 @fcmp_oge(float %a, float %b) nounwind {
 ; RV64I-NEXT:    addi sp, sp, -16
 ; RV64I-NEXT:    sd ra, 8(sp) # 8-byte Folded Spill
 ; RV64I-NEXT:    call __gesf2 at plt
-; RV64I-NEXT:    sext.w a0, a0
 ; RV64I-NEXT:    addi a1, zero, -1
 ; RV64I-NEXT:    slt a0, a1, a0
 ; RV64I-NEXT:    ld ra, 8(sp) # 8-byte Folded Reload
@@ -214,8 +210,7 @@ define float @fcvt_s_wu(i32 %a) nounwind {
 ; RV64I:       # %bb.0:
 ; RV64I-NEXT:    addi sp, sp, -16
 ; RV64I-NEXT:    sd ra, 8(sp) # 8-byte Folded Spill
-; RV64I-NEXT:    slli a0, a0, 32
-; RV64I-NEXT:    srli a0, a0, 32
+; RV64I-NEXT:    sext.w a0, a0
 ; RV64I-NEXT:    call __floatunsisf at plt
 ; RV64I-NEXT:    ld ra, 8(sp) # 8-byte Folded Reload
 ; RV64I-NEXT:    addi sp, sp, 16
@@ -675,8 +670,7 @@ define float @fpowi_s(float %a, i32 %b) nounwind {
 ; RV64I:       # %bb.0:
 ; RV64I-NEXT:    addi sp, sp, -16
 ; RV64I-NEXT:    sd ra, 8(sp) # 8-byte Folded Spill
-; RV64I-NEXT:    slli a1, a1, 32
-; RV64I-NEXT:    srli a1, a1, 32
+; RV64I-NEXT:    sext.w a1, a1
 ; RV64I-NEXT:    call __powisf2 at plt
 ; RV64I-NEXT:    ld ra, 8(sp) # 8-byte Folded Reload
 ; RV64I-NEXT:    addi sp, sp, 16