Most PPC M[TF]CR instructions do not have side effects
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178978 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCInstrInfo.td b/lib/Target/PowerPC/PPCInstrInfo.td
index 14f35ef..5853681 100644
--- a/lib/Target/PowerPC/PPCInstrInfo.td
+++ b/lib/Target/PowerPC/PPCInstrInfo.td
@@ -1337,6 +1337,7 @@
def RESTORE_VRSAVE : Pseudo<(outs VRSAVERC:$vrsave), (ins memri:$F),
"#RESTORE_VRSAVE", []>;
+let neverHasSideEffects = 1 in {
def MTCRF : XFXForm_5<31, 144, (outs crbitm:$FXM), (ins GPRC:$rS),
"mtcrf $FXM, $rS", BrMCRX>,
PPC970_MicroCode, PPC970_Unit_CRU;
@@ -1355,14 +1356,20 @@
def MFCRpseud: XFXForm_3<31, 19, (outs GPRC:$rT), (ins crbitm:$FXM),
"#MFCRpseud", SprMFCR>,
PPC970_MicroCode, PPC970_Unit_CRU;
-
-def MFCR : XFXForm_3<31, 19, (outs GPRC:$rT), (ins),
- "mfcr $rT", SprMFCR>,
- PPC970_MicroCode, PPC970_Unit_CRU;
def MFOCRF: XFXForm_5a<31, 19, (outs GPRC:$rT), (ins crbitm:$FXM),
"mfocrf $rT, $FXM", SprMFCR>,
PPC970_DGroup_First, PPC970_Unit_CRU;
+} // neverHasSideEffects = 1
+
+// MFCR uses all CR registers, but marking that explicitly causes
+// problems because some of them appear to be undefined. Because
+// this form is used only in prologue code, just mark it as having
+// side effects.
+let /* Uses = [CR0, CR1, CR2, CR3, CR4, CR5, CR6] */ hasSideEffects = 1 in
+def MFCR : XFXForm_3<31, 19, (outs GPRC:$rT), (ins),
+ "mfcr $rT", SprMFCR>,
+ PPC970_MicroCode, PPC970_Unit_CRU;
// Pseudo instruction to perform FADD in round-to-zero mode.
let usesCustomInserter = 1, Uses = [RM] in {