[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).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185529 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 130 insertions, 0 deletions

diff --git a/test/CodeGen/SystemZ/fp-mul-04.ll b/test/CodeGen/SystemZ/fp-mul-04.ll
index 712ead8..c7f734f 100644
--- a/test/CodeGen/SystemZ/fp-mul-04.ll
+++ b/test/CodeGen/SystemZ/fp-mul-04.ll
@@ -2,6 +2,8 @@
 ;
 ; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
 
+declare double @foo()
+
 ; Check register multiplication.  "mxdbr %f0, %f2" is not valid from LLVM's
 ; point of view, because %f2 is the low register of the FP128 %f0.  Pass the
 ; multiplier in %f4 instead.
@@ -101,3 +103,131 @@ define void @f6(double %f1, double *%base, i64 %index, fp128 *%dst) {
   store fp128 %res, fp128 *%dst
   ret void
 }
+
+; Check that multiplications of spilled values can use MXDB rather than MXDBR.
+define double @f7(double *%ptr0) {
+; CHECK: f7:
+; CHECK: brasl %r14, foo@PLT
+; CHECK: mxdb %f0, 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
+
+  %frob0 = fadd double %val0, %val0
+  %frob1 = fadd double %val1, %val1
+  %frob2 = fadd double %val2, %val2
+  %frob3 = fadd double %val3, %val3
+  %frob4 = fadd double %val4, %val4
+  %frob5 = fadd double %val5, %val5
+  %frob6 = fadd double %val6, %val6
+  %frob7 = fadd double %val7, %val7
+  %frob8 = fadd double %val8, %val8
+  %frob9 = fadd double %val9, %val9
+  %frob10 = fadd double %val9, %val10
+
+  store double %frob0, double *%ptr0
+  store double %frob1, double *%ptr1
+  store double %frob2, double *%ptr2
+  store double %frob3, double *%ptr3
+  store double %frob4, double *%ptr4
+  store double %frob5, double *%ptr5
+  store double %frob6, double *%ptr6
+  store double %frob7, double *%ptr7
+  store double %frob8, double *%ptr8
+  store double %frob9, double *%ptr9
+  store double %frob10, double *%ptr10
+
+  %ret = call double @foo()
+
+  %accext0 = fpext double %ret to fp128
+  %ext0 = fpext double %frob0 to fp128
+  %mul0 = fmul fp128 %accext0, %ext0
+  %const0 = fpext double 1.01 to fp128
+  %extra0 = fmul fp128 %mul0, %const0
+  %trunc0 = fptrunc fp128 %extra0 to double
+
+  %accext1 = fpext double %trunc0 to fp128
+  %ext1 = fpext double %frob1 to fp128
+  %mul1 = fmul fp128 %accext1, %ext1
+  %const1 = fpext double 1.11 to fp128
+  %extra1 = fmul fp128 %mul1, %const1
+  %trunc1 = fptrunc fp128 %extra1 to double
+
+  %accext2 = fpext double %trunc1 to fp128
+  %ext2 = fpext double %frob2 to fp128
+  %mul2 = fmul fp128 %accext2, %ext2
+  %const2 = fpext double 1.21 to fp128
+  %extra2 = fmul fp128 %mul2, %const2
+  %trunc2 = fptrunc fp128 %extra2 to double
+
+  %accext3 = fpext double %trunc2 to fp128
+  %ext3 = fpext double %frob3 to fp128
+  %mul3 = fmul fp128 %accext3, %ext3
+  %const3 = fpext double 1.31 to fp128
+  %extra3 = fmul fp128 %mul3, %const3
+  %trunc3 = fptrunc fp128 %extra3 to double
+
+  %accext4 = fpext double %trunc3 to fp128
+  %ext4 = fpext double %frob4 to fp128
+  %mul4 = fmul fp128 %accext4, %ext4
+  %const4 = fpext double 1.41 to fp128
+  %extra4 = fmul fp128 %mul4, %const4
+  %trunc4 = fptrunc fp128 %extra4 to double
+
+  %accext5 = fpext double %trunc4 to fp128
+  %ext5 = fpext double %frob5 to fp128
+  %mul5 = fmul fp128 %accext5, %ext5
+  %const5 = fpext double 1.51 to fp128
+  %extra5 = fmul fp128 %mul5, %const5
+  %trunc5 = fptrunc fp128 %extra5 to double
+
+  %accext6 = fpext double %trunc5 to fp128
+  %ext6 = fpext double %frob6 to fp128
+  %mul6 = fmul fp128 %accext6, %ext6
+  %const6 = fpext double 1.61 to fp128
+  %extra6 = fmul fp128 %mul6, %const6
+  %trunc6 = fptrunc fp128 %extra6 to double
+
+  %accext7 = fpext double %trunc6 to fp128
+  %ext7 = fpext double %frob7 to fp128
+  %mul7 = fmul fp128 %accext7, %ext7
+  %const7 = fpext double 1.71 to fp128
+  %extra7 = fmul fp128 %mul7, %const7
+  %trunc7 = fptrunc fp128 %extra7 to double
+
+  %accext8 = fpext double %trunc7 to fp128
+  %ext8 = fpext double %frob8 to fp128
+  %mul8 = fmul fp128 %accext8, %ext8
+  %const8 = fpext double 1.81 to fp128
+  %extra8 = fmul fp128 %mul8, %const8
+  %trunc8 = fptrunc fp128 %extra8 to double
+
+  %accext9 = fpext double %trunc8 to fp128
+  %ext9 = fpext double %frob9 to fp128
+  %mul9 = fmul fp128 %accext9, %ext9
+  %const9 = fpext double 1.91 to fp128
+  %extra9 = fmul fp128 %mul9, %const9
+  %trunc9 = fptrunc fp128 %extra9 to double
+
+  ret double %trunc9
+}