[MachineInstrBuilder] Support for adding a ConstantPoolIndex MO with an additional offset.

MachineInstrBuilder::addDisp can already add an immediate or global address MO with an adjusted offset, this patch adds support for constant pool indices as well.

All remaining MO types still assert - there are a number of other types that could support adjusted offsets but I have no test cases at this time.

Required to fix a regression in D13988 found by Mikael Holmén during stress testing (test case attached).

Differential Revision: http://reviews.llvm.org/D14867

llvm-svn: 253795

1 files changed, 20 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/X86/insertps-from-constantpool.ll b/llvm/test/CodeGen/X86/insertps-from-constantpool.ll
new file mode 100644
index 00000000000..cfcfeacad06
--- /dev/null
+++ b/llvm/test/CodeGen/X86/insertps-from-constantpool.ll
@@ -0,0 +1,20 @@
+; RUN: llc -mtriple=i686-unknown-unknown -mattr=+sse4.1 < %s | FileCheck %s --check-prefix=X32
+; RUN: llc -mtriple=x86_64-unknown-unknown -mattr=+sse4.1 < %s | FileCheck %s --check-prefix=X64
+
+; Test for case where insertps folds the load of an insertion element from a constant pool.
+
+define <4 x float> @fold_from_constantpool(<4 x float> %a) {
+; X32-LABEL: fold_from_constantpool:
+; X32:       # BB#0:
+; X32-NEXT:    insertps {{.*#+}} xmm0 = mem[0],xmm0[1,2,3]
+; X32-NEXT:    retl
+;
+; X64-LABEL: fold_from_constantpool:
+; X64:       # BB#0:
+; X64-NEXT:    insertps {{.*#+}} xmm0 = mem[0],xmm0[1,2,3]
+; X64-NEXT:    retq
+  %1 = call <4 x float> @llvm.x86.sse41.insertps(<4 x float> %a, <4 x float> <float 0.0, float 1.0, float 0.0, float 0.0>, i8 64)
+  ret <4 x float> %1
+}
+
+declare <4 x float> @llvm.x86.sse41.insertps(<4 x float>, <4 x float>, i8) nounwind readnone