From: lkcl <lkcl@web>
Date: Sat, 23 Jul 2022 12:21:38 +0000 (+0100)
Subject: (no commit message)
X-Git-Tag: opf_rfc_ls005_v1~1089
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=5e85449e43e61a62b1db2fe6035ba334430aa336;p=libreriscv.git

---

diff --git a/docs/pypowersim.mdwn b/docs/pypowersim.mdwn
index d27b12811..85e67e2d2 100644
--- a/docs/pypowersim.mdwn
+++ b/docs/pypowersim.mdwn
@@ -45,6 +45,28 @@ There are other options available (such as initialising the Floating Point
 Registers).
 for 
 
+**Example GPR file**:
+
+See <https://git.libre-soc.org/?p=openpower-isa.git;a=blob;f=media/audio/mp3/mp3_0.gpr;hb=HEAD>
+
+This file sets the GPRs to explicit values prior to execution.
+This allows for example a function call's parameters, according
+to Power ISA [ABI](), to be set conveniently and quickly, but
+more importantly without requiring execution of additional
+instructions.
+
+```
+   1 # void ff_mpadsp_apply_window_float(float *synth_buf, float *window,
+   2 #                                  int *dither_state, float *samples,
+   3 #                                  ptrdiff_t incr);
+   4 1: 0x8000        # stack pointer
+   5 3: 0x600000      # param 1: float *sunth_buf     buf
+   6 4: 0x700000      # param 2: float *window        win
+   7 5: 0x800000      # param 3: int *dither_state    &unused
+   8 6: 0x900000      # param 3: float *samples       out
+   9 7: 1             # param 5: ptr_diff_t incr      1
+```
+
 ### Before running the tests!
 
 **NOTE**: Is this correct?