[ARM] Permit auto-vectorization using MVE

With enough codegen complete, we can now correctly report the number and size
of vector registers for MVE, allowing auto vectorisation. This also allows FP
auto-vectorization for MVE without -Ofast/-ffast-math, due to support for IEEE
FP arithmetic and parity between scalar and vector FP behaviour.

Patch by David Sherwood.

Differential Revision: https://reviews.llvm.org/D63728

llvm-svn: 368529

diff --git a/llvm/lib/Target/ARM/ARMTargetTransformInfo.h b/llvm/lib/Target/ARM/ARMTargetTransformInfo.h
index 52f6ea4..b966c76 100644 (file)
--- a/llvm/lib/Target/ARM/ARMTargetTransformInfo.h
+++ b/llvm/lib/Target/ARM/ARMTargetTransformInfo.h
@@ -101,9 +101,9 @@ public:
 
   /// Floating-point computation using ARMv8 AArch32 Advanced
   /// SIMD instructions remains unchanged from ARMv7. Only AArch64 SIMD
-  /// is IEEE-754 compliant, but it's not covered in this target.
+  /// and Arm MVE are IEEE-754 compliant.
   bool isFPVectorizationPotentiallyUnsafe() {
-    return !ST->isTargetDarwin();
+    return !ST->isTargetDarwin() && !ST->hasMVEFloatOps();
   }
 
   /// \name Scalar TTI Implementations
@@ -126,6 +126,8 @@ public:
     if (Vector) {
       if (ST->hasNEON())
         return 16;
+      if (ST->hasMVEIntegerOps())
+        return 8;
       return 0;
     }
 
@@ -138,6 +140,8 @@ public:
     if (Vector) {
       if (ST->hasNEON())
         return 128;
+      if (ST->hasMVEIntegerOps())
+        return 128;
       return 0;
     }
 

diff --git a/llvm/test/Transforms/LoopVectorize/ARM/arm-ieee-vectorize.ll b/llvm/test/Transforms/LoopVectorize/ARM/arm-ieee-vectorize.ll
index 369568f..2a7a2ce 100644 (file)
--- a/llvm/test/Transforms/LoopVectorize/ARM/arm-ieee-vectorize.ll
+++ b/llvm/test/Transforms/LoopVectorize/ARM/arm-ieee-vectorize.ll
@@ -1,5 +1,6 @@
 ; RUN: opt -mtriple armv7-linux-gnueabihf -loop-vectorize -S %s -debug-only=loop-vectorize -o /dev/null 2>&1 | FileCheck %s --check-prefix=CHECK --check-prefix=LINUX
 ; RUN: opt -mtriple armv8-linux-gnu -loop-vectorize -S %s -debug-only=loop-vectorize -o /dev/null 2>&1 | FileCheck %s --check-prefix=CHECK --check-prefix=LINUX
+; RUN: opt -mtriple armv8.1.m-none-eabi -mattr=+mve.fp -loop-vectorize -S %s -debug-only=loop-vectorize -o /dev/null 2>&1 | FileCheck %s --check-prefix=CHECK --check-prefix=MVE
 ; RUN: opt -mtriple armv7-unknwon-darwin -loop-vectorize -S %s -debug-only=loop-vectorize -o /dev/null 2>&1 | FileCheck %s --check-prefix=CHECK --check-prefix=DARWIN
 ; REQUIRES: asserts
 
@@ -44,6 +45,8 @@ for.end:                                          ; preds = %for.end.loopexit, %
 ; Floating-point loops need fast-math to be vectorizeable
 ; LINUX: Checking a loop in "sumf"
 ; LINUX: Potentially unsafe FP op prevents vectorization
+; MVE: Checking a loop in "sumf"
+; MVE: We can vectorize this loop!
 ; DARWIN: Checking a loop in "sumf"
 ; DARWIN: We can vectorize this loop!
 define void @sumf(float* noalias nocapture readonly %A, float* noalias nocapture readonly %B, float* noalias nocapture %C, i32 %N) {
@@ -110,6 +113,8 @@ for.end:                                          ; preds = %for.end.loopexit, %
 ; Floating-point loops need fast-math to be vectorizeable
 ; LINUX: Checking a loop in "redf"
 ; LINUX: Potentially unsafe FP op prevents vectorization
+; MVE: Checking a loop in "redf"
+; MVE: We can vectorize this loop!
 ; DARWIN: Checking a loop in "redf"
 ; DARWIN: We can vectorize this loop!
 define float @redf(float* noalias nocapture readonly %a, float* noalias nocapture readonly %b, i32 %N) {