Index: lib/CodeGen/RegisterCoalescer.cpp =================================================================== --- lib/CodeGen/RegisterCoalescer.cpp +++ lib/CodeGen/RegisterCoalescer.cpp @@ -1582,6 +1582,14 @@ return false; } } + + // We must also check for overlaps with regmask clobbers. + BitVector RegMaskUsable; + if (LIS->checkRegMaskInterference(RHS, RegMaskUsable) && + !RegMaskUsable.test(DstReg)) { + DEBUG(dbgs() << "\t\tRegMask interference\n"); + return false; + } } // Skip any value computations, we are not adding new values to the @@ -1616,14 +1624,6 @@ DEBUG(dbgs() << "\t\tInterference (read): " << *MI); return false; } - - // We must also check for clobbers caused by regmasks. - for (const auto &MO : MI->operands()) { - if (MO.isRegMask() && MO.clobbersPhysReg(DstReg)) { - DEBUG(dbgs() << "\t\tInterference (regmask clobber): " << *MI); - return false; - } - } } } Index: test/CodeGen/SPARC/register-clobber.ll =================================================================== --- /dev/null +++ test/CodeGen/SPARC/register-clobber.ll @@ -0,0 +1,35 @@ +; RUN: llc -march=sparc < %s | FileCheck %s + +;; Verify that g1 (the output of first asm) is properly understood to +;; be clobbered by the call instruction, and moved out of the way +;; before it. (NOTE: remember delay slot; mov executes before call) + +; CHECK-LABEL: test1: +; CHECK: ta 9 +; CHECK: call dosomething +; CHECK: mov %g1, %i0 + +define i32 @test1() nounwind { +entry: + %0 = tail call i32 asm sideeffect "ta $1", "={r1},i"(i32 9) nounwind + tail call void @dosomething() nounwind + ret i32 %0 +} + +;; Also check using the value. +; CHECK-LABEL: test2: +; CHECK: ta 9 +; CHECK: call dosomething +; CHECK: mov %g1, %i0 +; CHECK: mov %i0, %g1 +; CHECK: ta 10 + +define void @test2() local_unnamed_addr nounwind { +entry: + %0 = tail call i32 asm sideeffect "ta $1", "={r1},i"(i32 9) nounwind + tail call void @dosomething() nounwind + tail call void asm sideeffect "ta $0", "i,{r1}"(i32 10, i32 %0) nounwind + ret void +} + +declare void @dosomething() local_unnamed_addr nounwind