Bitcasts between FP and INT values using direct moves

This patch corresponds to review:
http://reviews.llvm.org/D15286

LLVM IR frequently contains bitcast operations between floating point and
integer values of the same width. Doing this through memory operations is
quite expensive on PPC. This patch allows the use of direct register moves
between FPRs and GPRs for lowering bitcasts.

llvm-svn: 255246

2 files changed, 116 insertions, 2 deletions

diff --git a/llvm/test/CodeGen/PowerPC/p8-scalar_vector_conversions.ll b/llvm/test/CodeGen/PowerPC/p8-scalar_vector_conversions.ll
index 7e8991647ae..8da8df58a85 100644
--- a/llvm/test/CodeGen/PowerPC/p8-scalar_vector_conversions.ll
+++ b/llvm/test/CodeGen/PowerPC/p8-scalar_vector_conversions.ll
@@ -1036,7 +1036,7 @@ entry:
 ; CHECK-DAG: mfvsrd [[MOV:[0-9]+]],
 ; CHECK-DAG: li [[IMM3:[0-9]+]], 3
 ; CHECK-DAG: andc [[ANDC:[0-9]+]], [[IMM3]]
-; CHECK-DAG: rldicr [[SHL:[0-9]+]], [[ANDC]], 4, 60
+; CHECK-DAG: sldi [[SHL:[0-9]+]], [[ANDC]], 4
 ; CHECK-DAG: srd 3, [[MOV]], [[SHL]]
 ; CHECK-DAG: extsh 3, 3
 ; CHECK-LE-LABEL: @getvelss
@@ -1072,7 +1072,7 @@ entry:
 ; CHECK-DAG: mfvsrd [[MOV:[0-9]+]],
 ; CHECK-DAG: li [[IMM3:[0-9]+]], 3
 ; CHECK-DAG: andc [[ANDC:[0-9]+]], [[IMM3]]
-; CHECK-DAG: rldicr [[SHL:[0-9]+]], [[ANDC]], 4, 60
+; CHECK-DAG: sldi [[SHL:[0-9]+]], [[ANDC]], 4
 ; CHECK-DAG: srd 3, [[MOV]], [[SHL]]
 ; CHECK-DAG: clrldi   3, 3, 48
 ; CHECK-LE-LABEL: @getvelus
diff --git a/llvm/test/CodeGen/PowerPC/variable_elem_vec_extracts.ll b/llvm/test/CodeGen/PowerPC/variable_elem_vec_extracts.ll
new file mode 100644
index 00000000000..3d4789360f5
--- /dev/null
+++ b/llvm/test/CodeGen/PowerPC/variable_elem_vec_extracts.ll
@@ -0,0 +1,114 @@
+; RUN: llc -mcpu=pwr8 -mtriple=powerpc64le-unknown-unknown < %s | FileCheck %s
+; RUN: llc -mcpu=pwr8 -mtriple=powerpc64-unknown-unknown < %s | FileCheck %s \
+; RUN:  --check-prefix=CHECK-BE
+; RUN: llc -mcpu=pwr7 -mtriple=powerpc64-unknown-unknown < %s | FileCheck %s \
+; RUN:  --check-prefix=CHECK-P7
+
+; Function Attrs: norecurse nounwind readnone
+define signext i32 @geti(<4 x i32> %a, i32 signext %b) {
+entry:
+  %vecext = extractelement <4 x i32> %a, i32 %b
+  ret i32 %vecext
+; CHECK-LABEL: @geti
+; CHECK-P7-LABEL: @geti
+; CHECK-BE-LABEL: @geti
+; CHECK-DAG: li [[TRUNCREG:[0-9]+]], 2
+; CHECK-DAG: andc [[MASKREG:[0-9]+]], [[TRUNCREG]], 5
+; CHECK-DAG: sldi [[SHIFTREG:[0-9]+]], [[MASKREG]], 2
+; CHECK-DAG: lvsl [[SHMSKREG:[0-9]+]], 0, [[SHIFTREG]]
+; CHECK-DAG: vperm [[PERMVEC:[0-9]+]], 2, 2, [[SHMSKREG]]
+; CHECK-DAG: li [[ONEREG:[0-9]+]], 1
+; CHECK-DAG: and [[ELEMSREG:[0-9]+]], [[ONEREG]], 5
+; CHECK-DAG: sldi [[SHAMREG:[0-9]+]], [[ELEMSREG]], 5
+; CHECK: mfvsrd [[TOGPR:[0-9]+]],
+; CHECK: srd [[RSHREG:[0-9]+]], [[TOGPR]], [[SHAMREG]]
+; CHECK: extsw 3, [[RSHREG]]
+; CHECK-P7-DAG: sldi [[ELEMOFFREG:[0-9]+]], 5, 2
+; CHECK-P7-DAG: stxvw4x 34,
+; CHECK-P7: lwax 3, [[ELEMOFFREG]],
+; CHECK-BE-DAG: andi. [[ANDREG:[0-9]+]], 5, 2
+; CHECK-BE-DAG: sldi [[SLREG:[0-9]+]], [[ANDREG]], 2
+; CHECK-BE-DAG: lvsl [[SHMSKREG:[0-9]+]], 0, [[SLREG]]
+; CHECK-BE-DAG: vperm {{[0-9]+}}, 2, 2, [[SHMSKREG]]
+; CHECK-BE-DAG: li [[IMMREG:[0-9]+]], 1
+; CHECK-BE-DAG: andc [[ANDCREG:[0-9]+]], [[IMMREG]], 5
+; CHECK-BE-DAG: sldi [[SHAMREG:[0-9]+]], [[ANDCREG]], 5
+; CHECK-BE: mfvsrd [[TOGPR:[0-9]+]],
+; CHECK-BE: srd [[RSHREG:[0-9]+]], [[TOGPR]], [[SHAMREG]]
+; CHECk-BE: extsw 3, [[RSHREG]]
+}
+
+; Function Attrs: norecurse nounwind readnone
+define i64 @getl(<2 x i64> %a, i32 signext %b) {
+entry:
+  %vecext = extractelement <2 x i64> %a, i32 %b
+  ret i64 %vecext
+; CHECK-LABEL: @getl
+; CHECK-P7-LABEL: @getl
+; CHECK-BE-LABEL: @getl
+; CHECK-DAG: li [[TRUNCREG:[0-9]+]], 1
+; CHECK-DAG: andc [[MASKREG:[0-9]+]], [[TRUNCREG]], 5
+; CHECK-DAG: sldi [[SHIFTREG:[0-9]+]], [[MASKREG]], 3
+; CHECK-DAG: lvsl [[SHMSKREG:[0-9]+]], 0, [[SHIFTREG]]
+; CHECK-DAG: vperm [[PERMVEC:[0-9]+]], 2, 2, [[SHMSKREG]]
+; CHECK: mfvsrd 3,
+; CHECK-P7-DAG: sldi [[ELEMOFFREG:[0-9]+]], 5, 3
+; CHECK-P7-DAG: stxvd2x 34,
+; CHECK-P7: ldx 3, [[ELEMOFFREG]],
+; CHECK-BE-DAG: andi. [[ANDREG:[0-9]+]], 5, 1
+; CHECK-BE-DAG: sldi [[SLREG:[0-9]+]], [[ANDREG]], 3
+; CHECK-BE-DAG: lvsl [[SHMSKREG:[0-9]+]], 0, [[SLREG]]
+; CHECK-BE-DAG: vperm {{[0-9]+}}, 2, 2, [[SHMSKREG]]
+; CHECK-BE: mfvsrd 3,
+}
+
+; Function Attrs: norecurse nounwind readnone
+define float @getf(<4 x float> %a, i32 signext %b) {
+entry:
+  %vecext = extractelement <4 x float> %a, i32 %b
+  ret float %vecext
+; CHECK-LABEL: @getf
+; CHECK-P7-LABEL: @getf
+; CHECK-BE-LABEL: @getf
+; CHECK: li [[IMMREG:[0-9]+]], 3
+; CHECK: xor [[TRUNCREG:[0-9]+]], [[IMMREG]], 5
+; CHECK: lvsl [[SHMSKREG:[0-9]+]], 0, [[TRUNCREG]]
+; CHECK: vperm {{[0-9]+}}, 2, 2, [[SHMSKREG]]
+; CHECK: xscvspdpn 1,
+; CHECK-P7-DAG: sldi [[ELEMOFFREG:[0-9]+]], 5, 2
+; CHECK-P7-DAG: stxvw4x 34,
+; CHECK-P7: lfsx 1, [[ELEMOFFREG]],
+; CHECK-BE: sldi [[ELNOREG:[0-9]+]], 5, 2
+; CHECK-BE: lvsl [[SHMSKREG:[0-9]+]], 0, [[ELNOREG]]
+; CHECK-BE: vperm {{[0-9]+}}, 2, 2, [[SHMSKREG]]
+; CHECK-BE: xscvspdpn 1,
+}
+
+; Function Attrs: norecurse nounwind readnone
+define double @getd(<2 x double> %a, i32 signext %b) {
+entry:
+  %vecext = extractelement <2 x double> %a, i32 %b
+  ret double %vecext
+; CHECK-LABEL: @getd
+; CHECK-P7-LABEL: @getd
+; CHECK-BE-LABEL: @getd
+; CHECK: li [[TRUNCREG:[0-9]+]], 1
+; CHECK: andc [[MASKREG:[0-9]+]], [[TRUNCREG]], 5
+; CHECK: sldi [[SHIFTREG:[0-9]+]], [[MASKREG]], 3
+; CHECK: lvsl [[SHMSKREG:[0-9]+]], 0, [[SHIFTREG]]
+; CHECK: vperm {{[0-9]+}}, 2, 2, [[SHMSKREG]]
+; FIXME: the instruction below is a redundant regclass copy, to be removed
+; CHECK: xxlor 1,
+; CHECK-P7-DAG: andi. [[ANDREG:[0-9]+]], 5, 1
+; CHECK-P7-DAG: sldi [[SLREG:[0-9]+]], [[ANDREG]], 3
+; CHECK-P7-DAG: lvsl [[SHMSKREG:[0-9]+]], 0, [[SLREG]]
+; CHECK-P7-DAG: vperm {{[0-9]+}}, 2, 2, [[SHMSKREG]]
+; FIXME: the instruction below is a redundant regclass copy, to be removed
+; CHECK-P7: xxlor 1,
+; CHECK-BE-DAG: andi. [[ANDREG:[0-9]+]], 5, 1
+; CHECK-BE-DAG: sldi [[SLREG:[0-9]+]], [[ANDREG]], 3
+; CHECK-BE-DAG: lvsl [[SHMSKREG:[0-9]+]], 0, [[SLREG]]
+; CHECK-BE-DAG: vperm {{[0-9]+}}, 2, 2, [[SHMSKREG]]
+; FIXME: the instruction below is a redundant regclass copy, to be removed
+; CHECK-BE: xxlor 1,
+}