From: Segher Boessenkool <segher@kernel.crashing.org>
Date: Fri, 20 Dec 2019 00:15:19 +0000 (+0000)
Subject: rs6000: Use rldimi for 64-bit constants with high=low (PR93012)
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=72b2f3317b4484b25e9a6cc3fd12e7f8c893fb56;p=gcc.git

rs6000: Use rldimi for 64-bit constants with high=low (PR93012)

We currently use an (up to) five instruction sequence to generate such
constants.  After this change we just generate a 32-bit constant and do
a rotate-and-mask-insert instruction, making the sequence only up to
three instructions.

	* config/rs6000/rs6000.c (rs6000_emit_set_long_const): Handle the case
	where the low and the high 32 bits are equal to each other specially,
	with an rldimi instruction.

gcc/testsuite/
	* gcc.target/powerpc/pr93012.c: New.
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 302137eb29d..db03bf18242 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2020-02-06  Segher Boessenkool  <segher@kernel.crashing.org>
+
+	* config/rs6000/rs6000.c (rs6000_emit_set_long_const): Handle the case
+	where the low and the high 32 bits are equal to each other specially,
+	with an rldimi instruction.
+
 2020-02-06  Mihail Ionescu  <mihail.ionescu@arm.com>
 
 	* config/arm/arm-cpus.in: Set profile M for armv8.1-m.main.
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 74579568ee8..f2516a83842 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -9257,6 +9257,15 @@ rs6000_emit_set_long_const (rtx dest, HOST_WIDE_INT c)
 					   gen_lowpart (SImode,
 							copy_rtx (temp))));
     }
+  else if (ud1 == ud3 && ud2 == ud4)
+    {
+      temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode);
+      HOST_WIDE_INT num = (ud2 << 16) | ud1;
+      rs6000_emit_set_long_const (temp, (num ^ 0x80000000) - 0x80000000);
+      rtx one = gen_rtx_AND (DImode, temp, GEN_INT (0xffffffff));
+      rtx two = gen_rtx_ASHIFT (DImode, temp, GEN_INT (32));
+      emit_move_insn (dest, gen_rtx_IOR (DImode, one, two));
+    }
   else if ((ud4 == 0xffff && (ud3 & 0x8000))
 	   || (ud4 == 0 && ! (ud3 & 0x8000)))
     {
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 9c208d09c49..fd80c8d0f32 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2020-02-06  Segher Boessenkool  <segher@kernel.crashing.org>
+
+	* gcc.target/powerpc/pr93012.c: New.
+
 2020-02-06  Richard Sandiford  <richard.sandiford@arm.com>
 
 	PR target/87763
diff --git a/gcc/testsuite/gcc.target/powerpc/pr93012.c b/gcc/testsuite/gcc.target/powerpc/pr93012.c
new file mode 100644
index 00000000000..4f764d0576f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pr93012.c
@@ -0,0 +1,13 @@
+/* PR target/93012 */
+/* { dg-do compile { target lp64 } } */
+/* { dg-options "-O2 -std=c99" } */
+
+unsigned long long msk66() { return 0x6666666666666666ULL; }
+unsigned long long mskih() { return 0xabcd1234abcd1234ULL; }
+unsigned long long mskh0() { return 0x0000123400001234ULL; }
+unsigned long long mskl0() { return 0xabcd0000abcd0000ULL; }
+unsigned long long mskh1() { return 0xffff9234ffff9234ULL; }
+unsigned long long mskl1() { return 0x2bcdffff2bcdffffULL; }
+unsigned long long mskse() { return 0xffff1234ffff1234ULL; }
+
+/* { dg-final { scan-assembler-times {\mrldimi\M} 7 } } */