Merging r196370:
------------------------------------------------------------------------
r196370 | rsandifo | 2013-12-04 09:59:57 +0000 (Wed, 04 Dec 2013) | 14 lines
[SystemZ] Fix handling of pass-by-pointer arguments
I'd misunderstood getIndirect() to mean that the argument should be passed
as a pointer at the ABI level, with the ByVal argument choosing caller-copy
semantics over no-caller-copy (callee-copy-on-write) semantics. But
getIndirect(x) actually means that x is passed by pointer at the IR
level but (at least on all other targets I looked at) directly at the
ABI level. getIndirect(x, false) selects a pointer to a caller-made
copy, which is what SystemZ was aiming for.
This fixes a miscompilation of c-index-test. Structure arguments were being
passed by pointer, but no copy was being made, so a write in the callee
stomped over a caller's local variable.
------------------------------------------------------------------------
git-svn-id: https://llvm.org/svn/llvm-project/cfe/branches/release_34@196371 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/TargetInfo.cpp b/lib/CodeGen/TargetInfo.cpp
index 3d0c9f1..76acf87 100644
--- a/lib/CodeGen/TargetInfo.cpp
+++ b/lib/CodeGen/TargetInfo.cpp
@@ -4573,7 +4573,7 @@
// Values that are not 1, 2, 4 or 8 bytes in size are passed indirectly.
uint64_t Size = getContext().getTypeSize(Ty);
if (Size != 8 && Size != 16 && Size != 32 && Size != 64)
- return ABIArgInfo::getIndirect(0);
+ return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
// Handle small structures.
if (const RecordType *RT = Ty->getAs<RecordType>()) {
@@ -4581,7 +4581,7 @@
// fail the size test above.
const RecordDecl *RD = RT->getDecl();
if (RD->hasFlexibleArrayMember())
- return ABIArgInfo::getIndirect(0);
+ return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
// The structure is passed as an unextended integer, a float, or a double.
llvm::Type *PassTy;
@@ -4598,7 +4598,7 @@
// Non-structure compounds are passed indirectly.
if (isCompoundType(Ty))
- return ABIArgInfo::getIndirect(0);
+ return ABIArgInfo::getIndirect(0, /*ByVal=*/false);
return ABIArgInfo::getDirect(0);
}
diff --git a/test/CodeGen/systemz-inline-asm.c b/test/CodeGen/systemz-inline-asm.c
index eb0f912..c937233 100644
--- a/test/CodeGen/systemz-inline-asm.c
+++ b/test/CodeGen/systemz-inline-asm.c
@@ -123,7 +123,7 @@
long double test_f128(long double f, long double g) {
asm("axbr %0, %2" : "=f" (f) : "0" (f), "f" (g));
return f;
-// CHECK: define void @test_f128(fp128* noalias nocapture sret [[DEST:%.*]], fp128* byval nocapture readonly, fp128* byval nocapture readonly)
+// CHECK: define void @test_f128(fp128* noalias nocapture sret [[DEST:%.*]], fp128* nocapture readonly, fp128* nocapture readonly)
// CHECK: %f = load fp128* %0
// CHECK: %g = load fp128* %1
// CHECK: [[RESULT:%.*]] = tail call fp128 asm "axbr $0, $2", "=f,0,f"(fp128 %f, fp128 %g)