From: Jakub Jelinek <jakub@redhat.com>
Date: Tue, 1 Dec 2020 09:44:40 +0000 (+0100)
Subject: x86_64: Fix up -fpic -mcmodel=large -fno-plt [PR98063]
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=69157fe75823fc34f1e3265345f2d2b99cd8d380;p=gcc.git

x86_64: Fix up -fpic -mcmodel=large -fno-plt [PR98063]

On the following testcase with -fpic -mcmodel=large -fno-plt we emit
call puts@GOTPCREL(%rip)
but that is not really appropriate for CM_LARGE_PIC, the .text can be larger
than 2GB in that case and the .got slot further away from %rip than what can
fit into the signed 32-bit immediate.

The following patch computes the address of the .got slot the way it is
computed for that model for function pointer loads, and calls that.

2020-12-01  Jakub Jelinek  <jakub@redhat.com>

	PR target/98063
	* config/i386/i386-expand.c (ix86_expand_call): Handle non-plt
	CM_LARGE_PIC calls.

	* gcc.target/i386/pr98063.c: New test.
---

diff --git a/gcc/config/i386/i386-expand.c b/gcc/config/i386/i386-expand.c
index 408cd9baa78..bf775a38fc3 100644
--- a/gcc/config/i386/i386-expand.c
+++ b/gcc/config/i386/i386-expand.c
@@ -8063,7 +8063,17 @@ ix86_expand_call (rtx retval, rtx fnaddr, rtx callarg1,
 	    }
 	  else if (!TARGET_PECOFF && !TARGET_MACHO)
 	    {
-	      if (TARGET_64BIT)
+	      if (TARGET_64BIT
+		  && ix86_cmodel == CM_LARGE_PIC
+		  && DEFAULT_ABI != MS_ABI)
+		{
+		  fnaddr = gen_rtx_UNSPEC (Pmode, gen_rtvec (1, addr),
+					   UNSPEC_GOT);
+		  fnaddr = gen_rtx_CONST (Pmode, fnaddr);
+		  fnaddr = force_reg (Pmode, fnaddr);
+		  fnaddr = gen_rtx_PLUS (Pmode, pic_offset_table_rtx, fnaddr);
+		}
+	      else if (TARGET_64BIT)
 		{
 		  fnaddr = gen_rtx_UNSPEC (Pmode,
 					   gen_rtvec (1, addr),
diff --git a/gcc/testsuite/gcc.target/i386/pr98063.c b/gcc/testsuite/gcc.target/i386/pr98063.c
new file mode 100644
index 00000000000..f76435a7194
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr98063.c
@@ -0,0 +1,13 @@
+/* PR target/98063 */
+/* { dg-do run { target { i?86-*-linux* x86_64-*-linux* } } } */
+/* { dg-require-effective-target lp64 } */
+/* { dg-require-effective-target fpic } */
+/* { dg-options "-O2 -fpic -mcmodel=large -fno-plt -save-temps" } */
+/* { dg-final { scan-assembler-not "puts@GOTPCREL" } } */
+
+int
+main ()
+{
+  __builtin_puts ("Hello, world!");
+  return 0;
+}