MaskRay created this revision.
Herald added subscribers: vkmr, frasercrmck, evandro, luismarques, apazos,
sameer.abuasal, s.egerton, Jim, benna, psnobl, jocewei, PkmX, the_o,
brucehoult, MartinMosbeck, rogfer01, edward-jones, zzheng, jrtc27, shiva0217,
kito-cheng, niosHD, sabuasal, simoncook, johnrusso, rbar, asb, hiraditya.
MaskRay requested review of this revision.
Herald added projects: clang, LLVM.
Herald added subscribers: llvm-commits, cfe-commits.
Similar to D46745 <https://reviews.llvm.org/D46745>, "S" represents an absolute
symbolic operand, which
can be used to specify the access models, e.g.
extern int var;
void *addr_via_asm() {
void *ret;
asm("lui %0, %%hi(%1)\naddi %0,%0,%%lo(%1)" : "=r"(ret) : "S"(&var));
return ret;
}
We need 'S' to be documented on GCC:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101275
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D105254
Files:
clang/lib/Basic/Targets/RISCV.cpp
clang/test/CodeGen/RISCV/riscv-inline-asm.c
llvm/lib/Target/RISCV/RISCVISelLowering.cpp
llvm/test/CodeGen/RISCV/inline-asm-S-constraint.ll
Index: llvm/test/CodeGen/RISCV/inline-asm-S-constraint.ll
===================================================================
--- /dev/null
+++ llvm/test/CodeGen/RISCV/inline-asm-S-constraint.ll
@@ -0,0 +1,56 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mtriple=riscv32 < %s | FileCheck %s --check-prefix=RV32
+; RUN: llc -mtriple=riscv64 < %s | FileCheck %s --check-prefix=RV64
+
+@var = external dso_local global i32, align 4
+
+; Function Attrs: nofree nosync nounwind readnone
+define dso_local i8* @constraint_S() #1 {
+; RV32-LABEL: constraint_S:
+; RV32: # %bb.0: # %entry
+; RV32-NEXT: #APP
+; RV32-NEXT: lui a0, %hi(var)
+; RV32-NEXT: addi a0, a0, %lo(var)
+; RV32-NEXT: #NO_APP
+; RV32-NEXT: ret
+;
+; RV64-LABEL: constraint_S:
+; RV64: # %bb.0: # %entry
+; RV64-NEXT: #APP
+; RV64-NEXT: lui a0, %hi(var)
+; RV64-NEXT: addi a0, a0, %lo(var)
+; RV64-NEXT: #NO_APP
+; RV64-NEXT: ret
+entry:
+ %0 = tail call i8* asm "lui $0, %hi($1)\0Aaddi $0,$0,%lo($1)", "=r,S"(i32* nonnull @var)
+ ret i8* %0
+}
+
+; Function Attrs: nofree nosync nounwind readnone
+define dso_local i8* @constraint_S_label() #1 {
+; RV32-LABEL: constraint_S_label:
+; RV32: # %bb.0: # %entry
+; RV32-NEXT: .Ltmp0: # Block address taken
+; RV32-NEXT: # %bb.1: # %L1
+; RV32-NEXT: #APP
+; RV32-NEXT: lui a0, %hi(.Ltmp0)
+; RV32-NEXT: addi a0, a0, %lo(.Ltmp0)
+; RV32-NEXT: #NO_APP
+; RV32-NEXT: ret
+;
+; RV64-LABEL: constraint_S_label:
+; RV64: # %bb.0: # %entry
+; RV64-NEXT: .Ltmp0: # Block address taken
+; RV64-NEXT: # %bb.1: # %L1
+; RV64-NEXT: #APP
+; RV64-NEXT: lui a0, %hi(.Ltmp0)
+; RV64-NEXT: addi a0, a0, %lo(.Ltmp0)
+; RV64-NEXT: #NO_APP
+; RV64-NEXT: ret
+entry:
+ br label %L1
+
+L1: ; preds = %entry
+ %0 = tail call i8* asm "lui $0, %hi($1)\0Aaddi $0,$0,%lo($1)", "=r,S"(i8* blockaddress(@constraint_S_label, %L1))
+ ret i8* %0
+}
Index: llvm/lib/Target/RISCV/RISCVISelLowering.cpp
===================================================================
--- llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -8240,6 +8240,8 @@
return C_Immediate;
case 'A':
return C_Memory;
+ case 'S': // A symbolic address
+ return C_Other;
}
}
return TargetLowering::getConstraintType(Constraint);
@@ -8469,6 +8471,16 @@
DAG.getTargetConstant(CVal, SDLoc(Op), Subtarget.getXLenVT()));
}
return;
+ case 'S':
+ if (const GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(Op)) {
+ Ops.push_back(DAG.getTargetGlobalAddress(GA->getGlobal(), SDLoc(Op),
+ GA->getValueType(0)));
+ } else if (const BlockAddressSDNode *BA =
+ dyn_cast<BlockAddressSDNode>(Op)) {
+ Ops.push_back(DAG.getTargetBlockAddress(BA->getBlockAddress(),
+ BA->getValueType(0)));
+ }
+ return;
default:
break;
}
Index: clang/test/CodeGen/RISCV/riscv-inline-asm.c
===================================================================
--- clang/test/CodeGen/RISCV/riscv-inline-asm.c
+++ clang/test/CodeGen/RISCV/riscv-inline-asm.c
@@ -44,3 +44,9 @@
// CHECK: call void asm sideeffect "", "*A"(i32* %p)
asm volatile("" :: "A"(*p));
}
+
+void test_S() {
+// CHECK-LABEL: define{{.*}} void @test_S()
+// CHECK: call void asm sideeffect "", "S"(float* nonnull @f)
+ asm volatile("" :: "S"(&f));
+}
Index: clang/lib/Basic/Targets/RISCV.cpp
===================================================================
--- clang/lib/Basic/Targets/RISCV.cpp
+++ clang/lib/Basic/Targets/RISCV.cpp
@@ -87,6 +87,9 @@
// An address that is held in a general-purpose register.
Info.setAllowsMemory();
return true;
+ case 'S': // A symbolic address
+ Info.setAllowsRegister();
+ return true;
case 'v':
// A vector register.
if (Name[1] == 'r' || Name[1] == 'm') {
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
