[COMMITTED,MSP430] Tweaks to generation of 430X instructions

Message ID 20191024145508.212ac420@jozef-kubuntu
State New
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Series
  • [COMMITTED,MSP430] Tweaks to generation of 430X instructions
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Commit Message

Jozef Lawrynowicz Oct. 24, 2019, 1:55 p.m.
This patch makes a couple of simple tweaks to improve code generation for the
MSP430 430X ISA.

"Address-word instructions" support 20-bit operands without the extension word
required by regular 430X instructions. Using them where possible reduces code
size and improves performance.
We use the "Ya" constraint to indicate special cases the address-word "MOVA"
instruction can be used. The indirect auto-increment addressing mode can be
used with the source operand of a MOVA instructions, so this patch allows
the Ya constraint to match the (mem (post_inc)) RTX.

Similarly, the RRAM and RLAM rotate instructions do not use the extension word
that their RRAX and RLAX counterparts require. However, their use is limited to
shifting a register by a constant between 1 and 4 bits. This patch ensures they
get used when possible by extending the 430x_shift_left and
430x_arithmetic_shift_right insn patterns.

Successfully regtested for msp430-elf on trunk in the small and large memory
models.

Committed to trunk as obvious.

Patch

From 47e4f7397a43c86a7d483da1aa914018d52d9e5d Mon Sep 17 00:00:00 2001
From: jozefl <jozefl@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Thu, 24 Oct 2019 13:34:54 +0000
Subject: [PATCH] MSP430: Tweaks to generation of 430X instructions

gcc/ChangeLog:

2019-10-24  Jozef Lawrynowicz  <jozef.l@mittosystems.com>

	* config/msp430/constraints.md: Allow post_inc for "Ya" constraint.
	* config/msp430/msp430.md (430x_shift_left): Use RLAM when the constant
	shift amount is between 1 and 4.
	(430x_arithmetic_shift_right): Use RRAM when the constant shift amount
	is between 1 and 4.

gcc/testsuite/ChangeLog:

2019-10-24  Jozef Lawrynowicz  <jozef.l@mittosystems.com>

	* gcc.target/msp430/emulate-slli.c: Skip for -mcpu=msp430.
	Add shift by a constant 5 bits.
	Update scan-assembler directives.
	* gcc.target/msp430/emulate-srai.c: Likewise.
	* gcc.target/msp430/emulate-srli.c: Skip for -mcpu=msp430.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@277394 138bc75d-0d04-0410-961f-82ee72b054a4
---
 gcc/ChangeLog                                  |  8 ++++++++
 gcc/config/msp430/constraints.md               |  1 +
 gcc/config/msp430/msp430.md                    | 12 ++++++++----
 gcc/testsuite/ChangeLog                        |  8 ++++++++
 gcc/testsuite/gcc.target/msp430/emulate-slli.c |  6 +++++-
 gcc/testsuite/gcc.target/msp430/emulate-srai.c |  6 +++++-
 gcc/testsuite/gcc.target/msp430/emulate-srli.c |  1 +
 7 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d09b72d2b16..eb0a2f9b510 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@ 
+2019-10-24  Jozef Lawrynowicz  <jozef.l@mittosystems.com>
+
+	* config/msp430/constraints.md: Allow post_inc for "Ya" constraint.
+	* config/msp430/msp430.md (430x_shift_left): Use RLAM when the constant
+	shift amount is between 1 and 4.
+	(430x_arithmetic_shift_right): Use RRAM when the constant shift amount
+	is between 1 and 4.
+
 2019-10-24  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/92205
diff --git a/gcc/config/msp430/constraints.md b/gcc/config/msp430/constraints.md
index d01bcf9a242..49fc769ec74 100644
--- a/gcc/config/msp430/constraints.md
+++ b/gcc/config/msp430/constraints.md
@@ -82,6 +82,7 @@ 
 		  (match_test ("CONST_INT_P (XEXP (XEXP (op, 0), 1))"))
 		  (match_test ("IN_RANGE (INTVAL (XEXP (XEXP (op, 0), 1)), HOST_WIDE_INT_M1U << 15, (1 << 15)-1)"))))
 	(match_code "reg" "0")
+	(match_code "post_inc" "0")
 	)))
 
 (define_constraint "Yc"
diff --git a/gcc/config/msp430/msp430.md b/gcc/config/msp430/msp430.md
index e5ba445c60d..ed4c370261a 100644
--- a/gcc/config/msp430/msp430.md
+++ b/gcc/config/msp430/msp430.md
@@ -875,8 +875,10 @@ 
 		   (match_operand    2 "immediate_operand" "n")))]
   "msp430x"
   "*
-  if (INTVAL (operands[2]) > 0 && INTVAL (operands[2]) < 16)
-    return \"rpt\t%2 { rlax.w\t%0\";
+  if (INTVAL (operands[2]) > 0 && INTVAL (operands[2]) < 5)
+    return \"RLAM.W\t%2, %0\";
+  else if (INTVAL (operands[2]) >= 5 && INTVAL (operands[2]) < 16)
+    return \"RPT\t%2 { RLAX.W\t%0\";
   return \"# nop left shift\";
   "
 )
@@ -960,8 +962,10 @@ 
 		     (match_operand    2 "immediate_operand" "n")))]
   "msp430x"
   "*
-  if (INTVAL (operands[2]) > 0 && INTVAL (operands[2]) < 16)
-    return \"rpt\t%2 { rrax.w\t%0\";
+  if (INTVAL (operands[2]) > 0 && INTVAL (operands[2]) < 5)
+    return \"RRAM.W\t%2, %0\";
+  else if (INTVAL (operands[2]) >= 5 && INTVAL (operands[2]) < 16)
+    return \"RPT\t%2 { RRAX.W\t%0\";
   return \"# nop arith right shift\";
   "
 )
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 2742e10bb6f..ee43703ea54 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,11 @@ 
+2019-10-24  Jozef Lawrynowicz  <jozef.l@mittosystems.com>
+
+	* gcc.target/msp430/emulate-slli.c: Skip for -mcpu=msp430.
+	Add shift by a constant 5 bits.
+	Update scan-assembler directives.
+	* gcc.target/msp430/emulate-srai.c: Likewise.
+	* gcc.target/msp430/emulate-srli.c: Skip for -mcpu=msp430.
+
 2019-10-24  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/92205
diff --git a/gcc/testsuite/gcc.target/msp430/emulate-slli.c b/gcc/testsuite/gcc.target/msp430/emulate-slli.c
index 0ed09d55d8c..1c8459cfec5 100644
--- a/gcc/testsuite/gcc.target/msp430/emulate-slli.c
+++ b/gcc/testsuite/gcc.target/msp430/emulate-slli.c
@@ -1,15 +1,19 @@ 
 /* { dg-do compile } */
+/* { dg-skip-if "" { *-*-* } { "-mcpu=msp430" } { "" } } */
 /* { dg-options "-Os" } */
 /* { dg-final { scan-assembler-not "mspabi_slli" } } */
-/* { dg-final { scan-assembler "rlax" } } */
+/* { dg-final { scan-assembler "RLAM.W\t#4" } } */
+/* { dg-final { scan-assembler "RPT\t#5 \{ RLAX.W" } } */
 
 /* Ensure that HImode shifts with source operand in memory are emulated with a
    rotate instructions.  */
 
 int a;
+int b;
 
 void
 foo (void)
 {
   a = a << 4;
+  b = b << 5;
 }
diff --git a/gcc/testsuite/gcc.target/msp430/emulate-srai.c b/gcc/testsuite/gcc.target/msp430/emulate-srai.c
index 66291717a02..f3f6dae94ea 100644
--- a/gcc/testsuite/gcc.target/msp430/emulate-srai.c
+++ b/gcc/testsuite/gcc.target/msp430/emulate-srai.c
@@ -1,15 +1,19 @@ 
 /* { dg-do compile } */
+/* { dg-skip-if "" { *-*-* } { "-mcpu=msp430" } { "" } } */
 /* { dg-options "-Os" } */
 /* { dg-final { scan-assembler-not "mspabi_srai" } } */
-/* { dg-final { scan-assembler "rrax" } } */
+/* { dg-final { scan-assembler "RRAM.W\t#4" } } */
+/* { dg-final { scan-assembler "RPT\t#5 \{ RRAX.W" } } */
 
 /* Ensure that HImode shifts with source operand in memory are emulated with a
    rotate instructions.  */
 
 int a;
+int b;
 
 void
 foo (void)
 {
   a = a >> 4;
+  b = b >> 5;
 }
diff --git a/gcc/testsuite/gcc.target/msp430/emulate-srli.c b/gcc/testsuite/gcc.target/msp430/emulate-srli.c
index c10f30b2779..f870d13f86b 100644
--- a/gcc/testsuite/gcc.target/msp430/emulate-srli.c
+++ b/gcc/testsuite/gcc.target/msp430/emulate-srli.c
@@ -1,4 +1,5 @@ 
 /* { dg-do compile } */
+/* { dg-skip-if "" { *-*-* } { "-mcpu=msp430" } { "" } } */
 /* { dg-options "-Os" } */
 /* { dg-final { scan-assembler-not "mspabi_srli" } } */
 /* { dg-final { scan-assembler "rrum" } } */
-- 
2.17.1