jonpa updated this revision to Diff 298624.
jonpa added a comment.
That makes sense... Patch updated to keep the tying of operands for this case
of earlyclobber.
@nickdesaulniers : Can you see if this patch now passes your builds?
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D87279/new/
https://reviews.llvm.org/D87279
Files:
clang/lib/CodeGen/CGStmt.cpp
clang/test/CodeGen/systemz-inline-asm-02.c
clang/test/CodeGen/systemz-inline-asm.c
Index: clang/test/CodeGen/systemz-inline-asm.c
===================================================================
--- clang/test/CodeGen/systemz-inline-asm.c
+++ clang/test/CodeGen/systemz-inline-asm.c
@@ -129,3 +129,17 @@
// CHECK: [[RESULT:%.*]] = tail call fp128 asm "axbr $0, $2", "=f,0,f"(fp128 %f, fp128 %g)
// CHECK: store fp128 [[RESULT]], fp128* [[DEST]]
}
+
+// Test that there are no tied physreg uses. TwoAddress pass cannot deal with them.
+int test_physregs(void) {
+ // CHECK-LABEL: define signext i32 @test_physregs()
+ register int l __asm__("r7") = 0;
+
+ // CHECK: call i32 asm "lr $0, $1", "={r7},{r7}"
+ __asm__("lr %0, %1" : "+r"(l));
+
+ // CHECK: call i32 asm "$0 $1 $2", "={r7},{r7},{r7}"
+ __asm__("%0 %1 %2" : "+r"(l) : "r"(l));
+
+ return l;
+}
Index: clang/test/CodeGen/systemz-inline-asm-02.c
===================================================================
--- /dev/null
+++ clang/test/CodeGen/systemz-inline-asm-02.c
@@ -0,0 +1,13 @@
+// RUN: not %clang_cc1 -triple s390x-linux-gnu -O2 -emit-llvm -o - %s 2>&1 \
+// RUN: | FileCheck %s
+// REQUIRES: systemz-registered-target
+
+// Test that an error is given if a physreg is defined by multiple operands.
+int test_physreg_defs(void) {
+ register int l __asm__("r7") = 0;
+
+ // CHECK: error: multiple outputs to hard register: r7
+ __asm__("" : "+r"(l), "=r"(l));
+
+ return l;
+}
Index: clang/lib/CodeGen/CGStmt.cpp
===================================================================
--- clang/lib/CodeGen/CGStmt.cpp
+++ clang/lib/CodeGen/CGStmt.cpp
@@ -21,6 +21,7 @@
#include "clang/Basic/PrettyStackTrace.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/TargetInfo.h"
+#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/InlineAsm.h"
@@ -1836,7 +1837,8 @@
static std::string
AddVariableConstraints(const std::string &Constraint, const Expr &AsmExpr,
const TargetInfo &Target, CodeGenModule &CGM,
- const AsmStmt &Stmt, const bool EarlyClobber) {
+ const AsmStmt &Stmt, const bool EarlyClobber,
+ std::string *GCCReg = nullptr) {
const DeclRefExpr *AsmDeclRef = dyn_cast<DeclRefExpr>(&AsmExpr);
if (!AsmDeclRef)
return Constraint;
@@ -1861,6 +1863,8 @@
}
// Canonicalize the register here before returning it.
Register = Target.getNormalizedGCCRegisterName(Register);
+ if (GCCReg != nullptr)
+ *GCCReg = Register.str();
return (EarlyClobber ? "&{" : "{") + Register.str() + "}";
}
@@ -2059,6 +2063,9 @@
// Keep track of out constraints for tied input operand.
std::vector<std::string> OutputConstraints;
+ // Keep track of defined physregs.
+ llvm::SmallSet<std::string, 8> PhysRegOutputs;
+
// An inline asm can be marked readonly if it meets the following conditions:
// - it doesn't have any sideeffects
// - it doesn't clobber memory
@@ -2078,9 +2085,15 @@
const Expr *OutExpr = S.getOutputExpr(i);
OutExpr = OutExpr->IgnoreParenNoopCasts(getContext());
+ std::string GCCReg;
OutputConstraint = AddVariableConstraints(OutputConstraint, *OutExpr,
getTarget(), CGM, S,
- Info.earlyClobber());
+ Info.earlyClobber(),
+ &GCCReg);
+ // Give an error on multiple outputs to same physreg.
+ if (!GCCReg.empty() && !PhysRegOutputs.insert(GCCReg).second)
+ CGM.Error(S.getAsmLoc(), "multiple outputs to hard register: " + GCCReg);
+
OutputConstraints.push_back(OutputConstraint);
LValue Dest = EmitLValue(OutExpr);
if (!Constraints.empty())
@@ -2167,7 +2180,8 @@
LargestVectorWidth =
std::max((uint64_t)LargestVectorWidth,
VT->getPrimitiveSizeInBits().getKnownMinSize());
- if (Info.allowsRegister())
+ // Only tie earlyclobber physregs.
+ if (Info.allowsRegister() && (GCCReg.empty() || Info.earlyClobber()))
InOutConstraints += llvm::utostr(i);
else
InOutConstraints += OutputConstraint;
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