[SystemZ] Fold more spills
Add a mapping from register-based <INSN>R instructions to the corresponding
memory-based <INSN>. Use it to cut down on the number of spill loads.
Some instructions extend their operands from smaller fields, so this
required a new TSFlags field to say how big the unextended operand is.
This optimisation doesn't trigger for C(G)R and CL(G)R because in practice
we always combine those instructions with a branch. Adding a test for every
other case probably seems excessive, but it did catch a missed optimisation
for DSGF (fixed in r185435).
llvm-svn: 185529
diff --git a/llvm/test/CodeGen/SystemZ/fp-cmp-02.ll b/llvm/test/CodeGen/SystemZ/fp-cmp-02.ll
index 2987d50..c5bdd56 100644
--- a/llvm/test/CodeGen/SystemZ/fp-cmp-02.ll
+++ b/llvm/test/CodeGen/SystemZ/fp-cmp-02.ll
@@ -2,6 +2,8 @@
;
; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
+declare double @foo()
+
; Check comparison with registers.
define i64 @f1(i64 %a, i64 %b, double %f1, double %f2) {
; CHECK: f1:
@@ -87,3 +89,61 @@
%res = select i1 %cond, i64 %a, i64 %b
ret i64 %res
}
+
+; Check that comparisons of spilled values can use CDB rather than CDBR.
+define double @f7(double *%ptr0) {
+; CHECK: f7:
+; CHECK: brasl %r14, foo@PLT
+; CHECK: cdb {{%f[0-9]+}}, 160(%r15)
+; CHECK: br %r14
+ %ptr1 = getelementptr double *%ptr0, i64 2
+ %ptr2 = getelementptr double *%ptr0, i64 4
+ %ptr3 = getelementptr double *%ptr0, i64 6
+ %ptr4 = getelementptr double *%ptr0, i64 8
+ %ptr5 = getelementptr double *%ptr0, i64 10
+ %ptr6 = getelementptr double *%ptr0, i64 12
+ %ptr7 = getelementptr double *%ptr0, i64 14
+ %ptr8 = getelementptr double *%ptr0, i64 16
+ %ptr9 = getelementptr double *%ptr0, i64 18
+ %ptr10 = getelementptr double *%ptr0, i64 20
+
+ %val0 = load double *%ptr0
+ %val1 = load double *%ptr1
+ %val2 = load double *%ptr2
+ %val3 = load double *%ptr3
+ %val4 = load double *%ptr4
+ %val5 = load double *%ptr5
+ %val6 = load double *%ptr6
+ %val7 = load double *%ptr7
+ %val8 = load double *%ptr8
+ %val9 = load double *%ptr9
+ %val10 = load double *%ptr10
+
+ %ret = call double @foo()
+
+ %cmp0 = fcmp olt double %ret, %val0
+ %cmp1 = fcmp olt double %ret, %val1
+ %cmp2 = fcmp olt double %ret, %val2
+ %cmp3 = fcmp olt double %ret, %val3
+ %cmp4 = fcmp olt double %ret, %val4
+ %cmp5 = fcmp olt double %ret, %val5
+ %cmp6 = fcmp olt double %ret, %val6
+ %cmp7 = fcmp olt double %ret, %val7
+ %cmp8 = fcmp olt double %ret, %val8
+ %cmp9 = fcmp olt double %ret, %val9
+ %cmp10 = fcmp olt double %ret, %val10
+
+ %sel0 = select i1 %cmp0, double %ret, double 0.0
+ %sel1 = select i1 %cmp1, double %sel0, double 1.0
+ %sel2 = select i1 %cmp2, double %sel1, double 2.0
+ %sel3 = select i1 %cmp3, double %sel2, double 3.0
+ %sel4 = select i1 %cmp4, double %sel3, double 4.0
+ %sel5 = select i1 %cmp5, double %sel4, double 5.0
+ %sel6 = select i1 %cmp6, double %sel5, double 6.0
+ %sel7 = select i1 %cmp7, double %sel6, double 7.0
+ %sel8 = select i1 %cmp8, double %sel7, double 8.0
+ %sel9 = select i1 %cmp9, double %sel8, double 9.0
+ %sel10 = select i1 %cmp10, double %sel9, double 10.0
+
+ ret double %sel10
+}