Index: lib/CodeGen/RegUsageInfoCollector.cpp =================================================================== --- lib/CodeGen/RegUsageInfoCollector.cpp +++ lib/CodeGen/RegUsageInfoCollector.cpp @@ -110,19 +110,18 @@ // Scan all the physical registers. When a register is defined in the current // function set it and all the aliasing registers as defined in the regmask. for (unsigned PReg = 1, PRegE = TRI->getNumRegs(); PReg < PRegE; ++PReg) { - // If a register is in the UsedPhysRegsMask set then mark it as defined. - // All it's aliases will also be in the set, so we can skip setting - // as defined all the aliases here. - if (UsedPhysRegsMask.test(PReg)) { - SetRegAsDefined(PReg); - continue; - } // If a register is defined by an instruction mark it as defined together // with all it's aliases. if (!MRI->def_empty(PReg)) { for (MCRegAliasIterator AI(PReg, TRI, true); AI.isValid(); ++AI) SetRegAsDefined(*AI); + continue; } + // If a register is in the UsedPhysRegsMask set then mark it as defined. + // All clobbered aliases will also be in the set, so we can skip setting + // as defined all the aliases here. + if (UsedPhysRegsMask.test(PReg)) + SetRegAsDefined(PReg); } if (!TargetFrameLowering::isSafeForNoCSROpt(F)) { Index: test/CodeGen/SystemZ/ipra.ll =================================================================== --- /dev/null +++ test/CodeGen/SystemZ/ipra.ll @@ -0,0 +1,43 @@ +; Test that the set of used phys regs used by interprocedural register +; allocation is correct for a test case where the called function (@fn2) +; itself has a call (to @fn1). @fn1 defines %r0l, while @fn2 defines +; %r0d. The RegUsageInfo for @fn2 must include %r0h. +; +; RUN: llc -mtriple=s390x-linux-gnu -mcpu=z13 -enable-ipra -print-regusage 2>&1 < %s \ +; RUN: | FileCheck %s +; +; CHECK: fn2 Clobbered Registers: {{.*}} $r0h + +@h = external global [0 x i32], align 4 +@n = external global i32*, align 8 + +define void @fn1() { + br label %1 + +;