[PATCH v2] bpf: correct bpf_print_operand for floats [PR108293]

[David Faust <david.faust@oracle.com>]

Hi Jose,

As we discussed on IRC, since we don't currently define
TARGET_SUPPORTS_WIDE_INT it is safer to keep the handling for VOIDmode
CONST_DOUBLEs. My current understanding is that it may be needed if the
host is a 32-bit platform.

I also added a gcc_unreachable () as you pointed out. V2 below.
Tested with bpf-unknown-none on x86_64 host, no known regressions.

WDYT?

Thanks,
David

---

[Changes from v1:
 - Keep handling for VOIDmode CONST_DOUBLE, just in case.
 - Add a gcc_unreachable () if `op` is none of VOIDmode, SFmode,
   nor DFmode. ]

The existing logic in bpf_print_operand was only correct for integral
CONST_DOUBLEs, and emitted garbage for floating point modes. Fix it so
floating point mode operands are correctly handled.

	PR target/108293

gcc/

	* config/bpf/bpf.cc (bpf_print_operand): Correct handling for
	floating point modes.

gcc/testsuite/

	* gcc.target/bpf/double-1.c: New test.
	* gcc.target/bpf/double-2.c: New test.
	* gcc.target/bpf/float-1.c: New test.
---
 gcc/config/bpf/bpf.cc                   | 34 ++++++++++++++++++++-----
 gcc/testsuite/gcc.target/bpf/double-1.c | 12 +++++++++
 gcc/testsuite/gcc.target/bpf/double-2.c | 12 +++++++++
 gcc/testsuite/gcc.target/bpf/float-1.c  | 12 +++++++++
 4 files changed, 64 insertions(+), 6 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/bpf/double-1.c
 create mode 100644 gcc/testsuite/gcc.target/bpf/double-2.c
 create mode 100644 gcc/testsuite/gcc.target/bpf/float-1.c

diff --git a/gcc/config/bpf/bpf.cc b/gcc/config/bpf/bpf.cc
index 2aeaeaf309b..576a1fe8eab 100644
--- a/gcc/config/bpf/bpf.cc
+++ b/gcc/config/bpf/bpf.cc
@@ -880,13 +880,35 @@ bpf_print_operand (FILE *file, rtx op, int code ATTRIBUTE_UNUSED)
       output_address (GET_MODE (op), XEXP (op, 0));
       break;
     case CONST_DOUBLE:
-      if (CONST_DOUBLE_HIGH (op))
-	fprintf (file, HOST_WIDE_INT_PRINT_DOUBLE_HEX,
-		 CONST_DOUBLE_HIGH (op), CONST_DOUBLE_LOW (op));
-      else if (CONST_DOUBLE_LOW (op) < 0)
-	fprintf (file, HOST_WIDE_INT_PRINT_HEX, CONST_DOUBLE_LOW (op));
+      if (GET_MODE (op) == VOIDmode)
+	{
+	  if (CONST_DOUBLE_HIGH (op))
+	    fprintf (file, HOST_WIDE_INT_PRINT_DOUBLE_HEX,
+		     CONST_DOUBLE_HIGH (op), CONST_DOUBLE_LOW (op));
+	  else if (CONST_DOUBLE_LOW (op) < 0)
+	    fprintf (file, HOST_WIDE_INT_PRINT_HEX, CONST_DOUBLE_LOW (op));
+	  else
+	    fprintf (file, HOST_WIDE_INT_PRINT_DEC, CONST_DOUBLE_LOW (op));
+	}
       else
-	fprintf (file, HOST_WIDE_INT_PRINT_DEC, CONST_DOUBLE_LOW (op));
+	{
+	  long vals[2];
+	  real_to_target (vals, CONST_DOUBLE_REAL_VALUE (op), GET_MODE (op));
+	  vals[0] &= 0xffffffff;
+	  vals[1] &= 0xffffffff;
+	  if (GET_MODE (op) == SFmode)
+	    fprintf (file, "0x%08lx", vals[0]);
+	  else if (GET_MODE (op) == DFmode)
+	    {
+	      /* Note: real_to_target puts vals in target word order.  */
+	      if (WORDS_BIG_ENDIAN)
+		fprintf (file, "0x%08lx%08lx", vals[0], vals[1]);
+	      else
+		fprintf (file, "0x%08lx%08lx", vals[1], vals[0]);
+	    }
+	  else
+	    gcc_unreachable ();
+	}
       break;
     default:
       output_addr_const (file, op);
diff --git a/gcc/testsuite/gcc.target/bpf/double-1.c b/gcc/testsuite/gcc.target/bpf/double-1.c
new file mode 100644
index 00000000000..200f1bd18f8
--- /dev/null
+++ b/gcc/testsuite/gcc.target/bpf/double-1.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-mlittle-endian" } */
+
+double f;
+double a() { f = 1.0; return 1.0; }
+double b() { f = 2.0; return 2.0; }
+double c() { f = 2.0; return 3.0; }
+double d() { f = 3.0; return 3.0; }
+
+/* { dg-final { scan-assembler-times "lddw\t%r.,0x3ff0000000000000" 2 } } */
+/* { dg-final { scan-assembler-times "lddw\t%r.,0x4000000000000000" 3 } } */
+/* { dg-final { scan-assembler-times "lddw\t%r.,0x4008000000000000" 3 } } */
diff --git a/gcc/testsuite/gcc.target/bpf/double-2.c b/gcc/testsuite/gcc.target/bpf/double-2.c
new file mode 100644
index 00000000000..d04ddd0c575
--- /dev/null
+++ b/gcc/testsuite/gcc.target/bpf/double-2.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-mbig-endian" } */
+
+double f;
+double a() { f = 1.0; return 1.0; }
+double b() { f = 2.0; return 2.0; }
+double c() { f = 2.0; return 3.0; }
+double d() { f = 3.0; return 3.0; }
+
+/* { dg-final { scan-assembler-times "lddw\t%r.,0x3ff0000000000000" 2 } } */
+/* { dg-final { scan-assembler-times "lddw\t%r.,0x4000000000000000" 3 } } */
+/* { dg-final { scan-assembler-times "lddw\t%r.,0x4008000000000000" 3 } } */
diff --git a/gcc/testsuite/gcc.target/bpf/float-1.c b/gcc/testsuite/gcc.target/bpf/float-1.c
new file mode 100644
index 00000000000..05ed7bb651d
--- /dev/null
+++ b/gcc/testsuite/gcc.target/bpf/float-1.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-mlittle-endian" } */
+
+float f;
+float a() { f = 1.0; return 1.0; }
+float b() { f = 2.0; return 2.0; }
+float c() { f = 2.0; return 3.0; }
+float d() { f = 3.0; return 3.0; }
+
+/* { dg-final { scan-assembler-times "lddw\t%r.,0x3f800000" 2 } } */
+/* { dg-final { scan-assembler-times "lddw\t%r.,0x40000000" 3 } } */
+/* { dg-final { scan-assembler-times "lddw\t%r.,0x40400000" 3 } } */
-- 
2.39.0