[Arm] Disallow arm_movdi when targetting MVE

Without disabling this, the pattern can try and move DImode values
between floating point registers and general registers.
The constraints on this pattern can't handle that, and reload goes into
an infinite loop.

This was the cause of a testsuite failure in cde_v_1_mve.c, which is now
gone.

A DImode move for MVE now uses the `movdi_vfp` pattern, which is the same
pattern used for such a move when MVE is not available but the target has
TARGET_HARD_FLOAT.

Testing done:
    Bootstrapped and regtested on arm-none-linux-gnueabihf
    regtested on arm-none-eabi

gcc/ChangeLog:

2020-04-15  Matthew Malcomson  <matthew.malcomson@arm.com>

	* config/arm/arm.md (arm_movdi): Disallow for MVE.

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 2d6c5c88b7d1862fba9d13adf390e18c2e3d5b02..82e0cd61b00c816cdef5dc17db9058a1be098243 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,7 @@
+2020-04-15  Matthew Malcomson  <matthew.malcomson@arm.com>
+
+       * config/arm/arm.md (arm_movdi): Disallow for MVE.
+
 2020-04-15  Richard Biener  <rguenther@suse.de>
 
        PR middle-end/94539

diff --git a/gcc/config/arm/arm.md b/gcc/config/arm/arm.md
index 7bc55cce61b2e45e5875a233dd4546d59399d749..a6a31f8f4ef8d3c8c96c61b450dbd7c28d08b55c 100644 (file)
--- a/gcc/config/arm/arm.md
+++ b/gcc/config/arm/arm.md
@@ -6233,6 +6233,7 @@
        (match_operand:DI 1 "di_operand"              "rDa,Db,Dc,mi,r"))]
   "TARGET_32BIT
    && !(TARGET_HARD_FLOAT)
+   && !(TARGET_HAVE_MVE || TARGET_HAVE_MVE_FLOAT)
    && !TARGET_IWMMXT
    && (   register_operand (operands[0], DImode)
        || register_operand (operands[1], DImode))"